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Physics

CAIE2024

(a) State Newton’s law of gravitation. ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [2] (b) A planet may be considered as a uniform sphere. A satellite is in circular orbit of period T around the planet at a height h above the surface. The height of the orbit can be adjusted by use of the satellite’s rocket engines.

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Physics

CAIE2024

(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:2)(cid:2)(cid:44) (i) Determine the amplitude, in cm, of the oscillations. amplitude = ....................................................cm [1] (ii) Show that the angular frequency of the oscillations is 3.2 rad s–1. [2] (iii) Calculate the period T of the oscillations. T = .......................................................s [2] (iv) On Fig. 4.3, sketch the variation of h with time t from t = 0 to t = 6.0 s.

Question

Biology

CAIE2024

During aerobic respiration, cells respire substrates such as glucose to produce ATP. Some events that occur during aerobic respiration are: • The respiratory substrate breaks down into smaller and smaller molecules. These series of reactions are described as catabolism. • Coenzymes take part in various reactions. In some reactions, coenzymes are reduced or oxidised. • Carbon dioxide is released. (a) Aerobic respiration occurs in four successive stages: glycolysis (G), link reaction (LR), Krebs cycle (KC) and oxidative phosphorylation (OP). Complete Table 3.1 to show which events occur in each stage of aerobic respiration. Use a tick (✓) to show that the event does occur or a cross (✗) to show that the event does not occur. Table 3.1 stage event G LR KC OP catabolism coenzyme is reduced or oxidised a coenzyme forms a covalent bond with a respiratory intermediate carbon dioxide is released [4] (cid:300)(cid:209)(cid:266)(cid:190)(cid:288)(cid:180)(cid:237)(cid:200)(cid:245)(cid:207)(cid:298)(cid:197)(cid:266)(cid:222)(cid:250)(cid:182)(cid:254)(cid:215) © UCLES 2024 (cid:300)(cid:228)(cid:199)(cid:252)(cid:209)(cid:299)(cid:288)(cid:295)(cid:223)(cid:260)(cid:245)(cid:230)(cid:194)(cid:295)(cid:256)(cid:195)(cid:269)(cid:258) 9700/43/O/N/24 (cid:293)(cid:181)(cid:277)(cid:213)(cid:181)(cid:213)(cid:261)(cid:181)(cid:277)(cid:293)(cid:213)(cid:197)(cid:261)(cid:277)(cid:229)(cid:181)(cid:245)(cid:213) NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD PMT * 0000800000007 *

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Physics

CAIE2024

(a) State what is meant by the frequency of an alternating current. ................................................................................................................................................... ............................................................................................................................................. [1] (b) An alternating current I in a resistor of resistance 680 Ω varies with time t according to I = 3.5 sin (40πt) where I is in A and t is in s. (i) Show that the period of the alternating current is 50 ms. [1] (ii) On Fig. 8.1, sketch the variation of I with t between t = 0 and t = 100 ms.

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Physics

CAIE2024

2 T /s

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Biology

CAIE2024

During aerobic respiration, cells respire substrates such as glucose to produce ATP. Some events that occur during aerobic respiration are: • The respiratory substrate breaks down into smaller and smaller molecules. These series of reactions are described as catabolism. • Coenzymes take part in various reactions. In some reactions, coenzymes are reduced or oxidised. • Carbon dioxide is released. (a) Aerobic respiration occurs in four successive stages: glycolysis (G), link reaction (LR), Krebs cycle (KC) and oxidative phosphorylation (OP). Complete Table 3.1 to show which events occur in each stage of aerobic respiration. Use a tick (✓) to show that the event does occur or a cross (✗) to show that the event does not occur. Table 3.1 stage event G LR KC OP catabolism coenzyme is reduced or oxidised a coenzyme forms a covalent bond with a respiratory intermediate carbon dioxide is released [4] (cid:300)(cid:209)(cid:266)(cid:190)(cid:288)(cid:180)(cid:237)(cid:200)(cid:245)(cid:207)(cid:298)(cid:197)(cid:266)(cid:222)(cid:252)(cid:181)(cid:254)(cid:215) © UCLES 2024 (cid:300)(cid:298)(cid:183)(cid:242)(cid:209)(cid:294)(cid:255)(cid:283)(cid:223)(cid:260)(cid:266)(cid:211)(cid:206)(cid:218)(cid:253)(cid:267)(cid:240)(cid:258) 9700/41/O/N/24 (cid:293)(cid:229)(cid:245)(cid:277)(cid:181)(cid:181)(cid:197)(cid:181)(cid:245)(cid:261)(cid:293)(cid:197)(cid:261)(cid:277)(cid:293)(cid:213)(cid:277)(cid:213) NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD PMT * 0000800000007 *

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Physics

CAIE2024

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Biology

CAIE2024

(cid:44)(cid:1)(cid:1)(cid:1)(cid:1)(cid:9)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:1)(cid:4)(cid:44) (b) Fig. 1.2 shows an action potential in a rat neurone and Fig. 1.3 shows an action potential in a snail neurone. rat snail

Question

Biology

CAIE2024

The leaves of many plants have stomata that show a regular daily rhythm of opening and closing over a period of 24 hours. (a) Explain why it is important for plants to open and close their stomata in a daily rhythm. ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ................................................................................................................................................... ............................................................................................................................................. [3] (b) Fig. 2.1 shows the results of an experiment to monitor this rhythm over three days and nights for the plant Arabidopsis thaliana. The percentage of open stomata is shown. Each day consisted of 14 hours of light (white bar) and each night consisted of 10 hours of darkness (black bar). 100 Key day open night stomata 50 / %

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Biology

CAIE2024

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Biology

CAIE2024

27 26 X 27 CEP290 polypeptide product shortened CEP290 polypeptide Fig. 3.1 In 2022, research was carried out into possible treatment of LCA10 using genetic technology. (i) A human clinical trial investigated a treatment of LCA10 using a short RNA nucleotide sequence known as Sepofarsen. Sepofarsen binds to the section of the primary transcript containing the CEP290 mutation so that normal splicing occurs and functional CEP290 protein is synthesised. • People in the clinical trial received regular treatment with Sepofarsen to the eye with the greatest loss of vision (treated eye) for a period of 12 months. • Changes in the light perception (visual acuity) of both eyes were measured using a vision chart. • A negative change in the visual acuity score shows an improvement in visual acuity. Fig. 3.2 shows the results of the clinical trial over 12 months. (cid:300)(cid:209)(cid:266)(cid:190)(cid:288)(cid:180)(cid:237)(cid:200)(cid:245)(cid:207)(cid:298)(cid:197)(cid:266)(cid:222)(cid:252)(cid:182)(cid:254)(cid:215) © UCLES 2024 (cid:300)(cid:224)(cid:202)(cid:243)(cid:206)(cid:296)(cid:243)(cid:272)(cid:236)(cid:239)(cid:265)(cid:257)(cid:193)(cid:271)(cid:274)(cid:275)(cid:277)(cid:258) 9700/42/O/N/24 (cid:293)(cid:229)(cid:277)(cid:213)(cid:181)(cid:245)(cid:293)(cid:213)(cid:229)(cid:229)(cid:229)(cid:261)(cid:197)(cid:277)(cid:197)(cid:213)(cid:213)(cid:213) NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD NIGRAM SIHT NI ETIRW TON OD PMT * 0000800000007 *

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Biology

CAIE2024

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Physics

CAIE2024

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Mathematics

Edexcel2023

This question is about some Group 2 compounds. (a) Explain the trend in the thermal stability of carbonates in Group 2. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) Magnesium chloride is soluble in water. The enthalpy level diagram for the dissolving of magnesium chloride is Mg2+(g) + 2Cl–(g) – 2493 kJ mol–1 enthalpy MgCl (s)

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Mathematics

Edexcel2023

6 I Cl  ICl+ + ICl–

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Mathematics

Edexcel2023

Chlorine and bromine are elements in Group 7 of the Periodic Table. Both elements exist in a number of different oxidation numbers and therefore are involved in many redox reactions. (a) Write an equation for the reaction between chlorine and cold, dilute aqueous sodium hydroxide. State symbols are not required. (1) (b) Chlorine dioxide reacts with cold, dilute aqueous sodium hydroxide. The ionic equation for the reaction is: 2ClO (aq) + 2OH−(aq) → ClO –(aq) + ClO –(aq) + H O(l)

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Mathematics

Edexcel2023

6 2 4 (i) Draw a labelled diagram of a simple experiment to confirm this dissociation has occurred, stating the positive result. (2) Result .................................................................................................................................................................................................................................................................. (ii) What is the shape of the ICl– ion?

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Mathematics

Edexcel2023

6 When molten, it is suggested that it breaks down as shown. I Cl  ICl+ + ICl–

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Mathematics

Edexcel2023

*P71912A0428* PMT

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Physics

CAIE2023

For Examiner’s Use A mass of 1.00kg on the Equator rotates about the axis of the Earth with a period of

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Mathematics

Edexcel2023

Chemists often use the term ‘orbital’ when considering atomic structure. (a) State what is meant by the term orbital. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (b) Draw diagrams to show the shape of an s and a p orbital. (2) s orbital p orbital (c) What is the electronic configuration of a copper atom? (1) A [Ar]4s13d10 B [Ar]4s23d9 C [Ar]4s24p13d8 D [Ar]4s24p23d7 (Total for Question 2 = 5 marks) 

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Mathematics

Edexcel2023

Show outer shell electrons only. (1) (b) The solubility of oxygen in water under standard conditions is 1.22 × 10–3 mol dm–3. Comment on this value by considering the type and strength of the intermolecular forces in • pure water • pure oxygen • a mixture of water and oxygen. Detailed descriptions of the forces involved are not required. (4) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 

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Mathematics

Edexcel2023

• the liberated iodine was then titrated with sodium thiosulfate solution, Na S O (aq), of concentration 0.00518 mol dm–3

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Mathematics

Edexcel2023

2 3 4 6 • the mean volume of the titre of Na S O (aq) was 34.20 cm3.

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Mathematics

Edexcel2023

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Mathematics

Edexcel2023

(1) A octahedral B square planar C tetrahedral D trigonal bipyramidal (iii) The equilibrium position for the dissociation of molten I Cl lies to the left.

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Mathematics

Edexcel2023

3 Ionisation energy

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Mathematics

Edexcel2023

6 2 4 What is the most likely numerical value of K for this equilibrium? c (1) A 1.0 × 106 B 5.0 × 103 C 1.0 D 5.0 × 10–3 (Total for Question 3 = 9 marks) 

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Mathematics

Edexcel2023

The graph shows the melting temperatures of some elements in Period 3. 1800 1600 1400 1200 Melting 1000 temperature / K 800 600 400 200

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Mathematics

Edexcel2023

Na Mg Al Si P Elements in Period 3 Explain the variations in melting temperature across the period in terms of the structure and bonding in these elements. (6) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 

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Mathematics

Edexcel2023

All quantities are measured in kJ mol–1. –2969 2Ag+(g) + O2–(g) Ag O(s)

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Mathematics

Edexcel2023

Compare and contrast the role of the catalysts in these reactions. (6) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 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Mathematics

Edexcel2023

This question is about d‑block elements. (a) Which of the labels 1–4 identifies a d‑block element in Period 4?

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Mathematics

Edexcel2023

(4) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 7 = 13 marks) 

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Mathematics

Edexcel2023

7 2 Equilibrium 2 Cl (aq) + 2e–  2Cl–(aq) Ed = +1.36 V

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Mathematics

Edexcel2023

7 agent made the statement shown. ‘Standard electrode potential data shows that it is never feasible for a 1.00 mol dm–3 solution of potassium dichromate(VI) to oxidise the chloride ions in hydrochloric acid.’ Comment on this statement using the data and equilibria shown. Equilibrium 1 Cr O2–(aq) + 14H+(aq) + 6e–  2Cr3+(aq) + 7H O(l) Ed = +1.33 V

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Mathematics

Edexcel2023

*P71912A0228* PMT Answer ALL questions. Some questions must be answered with a cross in a box . If you change your mind about an answer, put a line through the box and then mark your new answer with a cross .

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Mathematics

Edexcel2023

4 by manganate(VII) ions, MnO–(aq).

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Mathematics

Edexcel2023

6 (i) State the colour of this complex ion. (1) .................................................................................................................................................................................................................................................................................... (ii) Explain why the aqueous solution of this complex ion has an acidic pH by considering the interaction between the metal ion and the ligands. (2) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 

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Mathematics

Edexcel2023

4 3 complex ion [Cr(H O) ]3+(aq).

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Mathematics

Edexcel2023

+798 +731 × 2 –141.1 –31 O(g) Δ Hd(Ag(s)) × 2 +249.2 at 2Ag(s) + ½O (g)

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Mathematics

Edexcel2023

(i) Complete the diagram by adding appropriate species and state symbols to the empty boxes. (2) (ii) Explain why the value for the first electron affinity of oxygen is negative and the value for the second electron affinity is positive. (3) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... 

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Mathematics

Edexcel2023

4 2 colourless brown (1) Position of equilibrium Change in colour A moves to the right mixture gets lighter B moves to the right mixture gets darker C moves to the left mixture gets lighter D moves to the left mixture gets darker (Total for Question 5 = 7 marks) 

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Mathematics

Edexcel2023

of river water • the Mn2+ ions reacted with the dissolved oxygen forming a precipitate of manganese(IV) oxide hydroxide 2Mn2+(aq) + O (aq) + 4OH–(aq) → 2MnO(OH) (s)

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Mathematics

Edexcel2023

2 • the precipitate was then dissolved using excess sulfuric acid, forming Mn4+(aq) ions MnO(OH) (s) + 4H+(aq) → Mn4+(aq) + 3H O(l)

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Mathematics

Edexcel2023

2 • excess potassium iodide solution was then added, forming iodine Mn4+(aq) + 2I–(aq) → Mn2+(aq) + I (aq)

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Mathematics

Edexcel2023

4 2 colourless brown (a) The table shows values of ΔG at different temperatures for this reaction. Temperature / K ΔG / kJ mol–1 350 –4.0 400 –13 450 –22 500 –31 550 –40 (i) Plot a graph of ΔG against temperature. (2) ΔG / kJ mol–1 Temperature / K 

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Mathematics

Edexcel2023

2 3 I (aq) + 2S O2–(aq) → 2I–(aq) + S O2–(aq)

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Mathematics

Edexcel2023

2 3 (i) Calculate the concentration of dissolved oxygen in the sample of river water, in g dm–3. (5) 

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Mathematics

Edexcel2023

2 B Mn3+(aq) + e–  Mn2+(aq) +1.51 Explain why Mn3+ ions are unstable in aqueous solution. Include an equation and the type of reaction that occurs. (4) .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... .................................................................................................................................................................................................................................................................................... (Total for Question 10 = 15 marks) TOTAL FOR PAPER = 90 MARKS 

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