Edexcel A Level Chemistry Paper 1: Advanced Inorganic and Physical Chemistry November 2021 question paper 9CH0/01

This is a question about atoms, isotopes and ions.

Which of the following pairs of ions is isoelectronic?

The percentage composition of the two bromine isotopes in a sample is given in the table.

Calculate the relative atomic mass of bromine in this sample. Give your answer to two decimal places.

Barium ions can be identified by their flame colour.

Which of the following should be used for a flame test on barium carbonate?

What colour do barium ions give in a flame test?

A flame test was carried out on a mixture of barium chloride and magnesium chloride.

How does the presence of magnesium ions affect the appearance of the flame colour of barium ions?

This question is about catalytic converters.

Catalytic converters contain metals such as platinum.

Describe the bonding in platinum. You may include a diagram in your answer.

A catalytic converter decreases the emissions of gases, such as carbon monoxide and nitrogen monoxide, from an internal combustion engine.

Describe the stages in a catalytic converter that result in this decrease. No equations are required.

Ionisation energies provide information about the number of electrons and the arrangement of the electrons in an atom of an element.

A student’s definition of first ionisation energy is shown.

There is one incorrect word in the student’s definition.

Identify the word, giving the reason why this word is incorrect.

Write an equation for the second ionisation energy of oxygen. Include state symbols.

A sodium atom has 11 protons whereas a potassium atom has 19 protons.

Explain why the first ionisation energy of sodium is greater than that of potassium.

The successive ionisation energies for magnesium are given in the table.

Complete the table.

Give a reason why the logarithm of the ionisation energy, rather than just the ionisation energy, is used to plot a graph.

Give a reason why the successive ionisation energies increase.

Plot the graph of log(ionisation energy) against electron number removed.

Join the individual points using straight lines.

Identify on the graph, using a circle, the points that represent the removal of the electrons in the outermost energy level of magnesium.

Estimate a value for the first ionisation energy of oxygen given the data in the table.

The halogens are elements in Group 7 of the Periodic Table.

Chlorine compounds have many uses, including water treatment.

Chlorine and phosphorus (P₄) can react to form phosphorus(V) chloride.

The structure of a molecule of phosphorus is

Some mean bond enthalpy values are shown in the table.

Calculate the enthalpy change for the reaction between chlorine and phosphorus to form phosphorus(V) chloride.

Give a reason why bond enthalpy values are always positive.

Sodium chlorate(I) is a bleaching agent.

Sodium chlorate(I) can be made by the reaction of chlorine with sodium hydroxide.

Show, by using oxidation numbers, that this reaction is disproportionation.

2NaOH + Cl₂ NaClO + NaCl + H₂O

A different bleaching agent can be made by the reaction of chlorine with sodium hydroxide under different conditions.

Balance this equation.

_........ NaOH +_........ Cl₂ NaClO₃ +_........ NaCl +_........ H₂O

What conditions are required for the reaction in (b)(ii)?

The halogens can be identified by their colour in an organic solvent such as hexane or cyclohexane.

Which sequence of colours is correct for chlorine, bromine and iodine dissolved in an organic solvent?

Halide ions can be identified by their reaction with silver nitrate.

Write the ionic equation for the reaction between aqueous solutions of sodium iodide and silver nitrate. Include state symbols.

A solution containing 0.010 mol of a halide ion was reacted with excess silver nitrate and produced 1.88 g of precipitate.

Identify the halide ion. Justify your answer.

This question is about entropy.

Give two reasons why you would expect Δ to be positive.

Explain why the wooden block is lifted up by the flask.

What is the standard molar entropy change, Δ , in J K^–1mol^–1, for the reaction shown?

This question is about acids and buffer solutions.

Ethanoic acid, CH₃COOH, is a monobasic acid.

Give a reason why only the proton from the carboxylic acid group, and not from the methyl group, is donated to a water molecule.

The reaction of ammonia with water can be represented by

Which is the acid‑conjugate base pair?

A commercial nitric acid solution, HNO₃(aq), has a concentration of 15.9 mol dm^–3. A 15.0 cm³ sample was made up to 100 cm³ by adding deionised water.

Calculate the pH of this diluted solution.

Propanoic acid is a weak acid.

Calculate the pH of a 0.100 mol dm^–3 solution of propanoic acid at 298 K. Give your answer to an appropriate number of significant figures.

[K_a = 1.3510^–5mol dm^–3 at 298 K]

State two assumptions that you made in the calculation in d(i).

A buffer solution was made using 20.0 cm³ of a butanoic acid solution, of concentration 0.100 mol dm^–3 and 30.0 cm³ of sodium butanoate solution, of concentration 0.305 mol dm^–3.

[K_a = 1.52×10^–5mol dm^–3 at 298K]

Calculate the pH of this buffer solution at 298 K.

Explain why the pH of the buffer solution hardly changes when a few drops of sodium hydroxide solution are added to it. Include an equation or equations in your answer. Use C₃H₇COOH as the formula for butanoic acid.

Transition metals form complex ions.

Complex ions have a central metal ion surrounded by ligands.

Give a reason why the ammonium ion cannot act as a ligand.

Explain why the complex ions [Co(NH₃)₆]²⁺ and [Co(H₂O)₆]²⁺ are coloured and have different colours.

Which of these complexes is used in the treatment of cancer?

Compare and contrast the complex ions formed by cobalt(III) ions with the ligand ethane‑1,2‑diamine and with the ligand EDTA^4–.

Ignore any difference in colour.

Hydrated chromium(III) chloride, CrCl₃.6H₂O, dissolves in water to form a number of different complex ions containing both chloride and water ligands.

The general formula of these complex ions is [Cr(H₂O)_x(Cl)_y]^(3–y)+

In an experiment, 0.10 mol of a complex reacted with excess silver nitrate solution to produce 0.20 mol of silver chloride.

Chloride ions which are ligands within the complex do not react with silver nitrate.

Deduce the formula of this chromium(III) complex ion. Justify your answer.

This question is about lattice energies.

The table shows the theoretical and experimental lattice energy values of two compounds.

State what can be deduced by the close similarity of the lattice energy values for barium iodide.

Explain why there is a significant difference in the lattice energy values for magnesium iodide.

Data for the Born‑Haber cycle for copper(II) oxide are given in the table.

Complete the diagram of the Born‑Haber cycle for copper(II) oxide.

Include labels of enthalpy changes with arrows indicating the direction of change, and the respective species with state symbols.

Calculate the lattice energy of copper(II) oxide.

A student wrote:

Discuss this statement.

Include reference to:

changes in the values and signs of the terms in the equation for both endothermic and exothermic reactions

circumstances where a reaction that is predicted to be thermodynamically feasible may not occur in practice.