7 questions · 70 marks · ≈ 70 min
Use the Periodic Table to answer these questions.
Give the name of the element with atomic number 16
Give the name of the element with relative atomic mass 9
Give the name of the element in Group 3 and Period 2
Give the electronic configuration of an atom of silicon.
Explain, in terms of electron configuration, why sodium is more reactive than lithium.
Structures made of iron can rust.
Name the two substances that cause iron to rust. 1 2
State a barrier method that prevents rusting.
Explain how sacrificial protection prevents the rusting of iron.
The diagram shows the separation of crude oil into fractions
Give the name of fraction A and the name of fraction F. fraction A fraction F
One of the fractions is kerosene.
Give one use of kerosene.
Describe how kerosene can be obtained from crude oil.
Catalytic cracking is a process used to break down fractions containing long‑chain molecules.
Give the name of the catalyst and the temperature used for catalytic cracking. catalyst temperature
Explain why catalytic cracking is useful.
The table shows the masses of two solids that dissolve in 100 g of water at different temperatures.
| Temperature in °C | 10 | 25 | 40 | 60 | 75 |
|---|---|---|---|---|---|
| Mass of potassium nitrate in g | 5 | 10 | 16 | 28 | 39 |
| Mass of sodium nitrate in g | 21 | 23 | 26 | 31 | 35 |
Plot the data for potassium nitrate and for sodium nitrate on the grid.
Draw and label a curve of best fit for KNO₃ and for NaNO₃ Mass of solute in g 10 20 30 40 50 60 70 80 Temperature in °C
The graph shows the temperature at which the maximum mass dissolved is the same for each solute. Determine this temperature. temperature = °C
Use your graph to calculate the solubility, in g per 100 g of water, of sodium nitrate at 30 °C. [1.0 cm³ of water has a mass of 1.0 g] solubility of sodium nitrate in g per 100 g of water =
25 cm³ of a saturated solution of potassium nitrate is cooled from 50 °C to 20 °C. Use your graph to determine the mass, in grams, of potassium nitrate that crystallises. Show your working on the graph. mass = g
Methanol, CH₃OH, is the first member of the homologous series of alcohols.
Give two characteristics of a homologous series. 1 2
Methanol is heated with potassium dichromate(VI) and one other reagent. The methanol is oxidised to methanoic acid, HCOOH
Give the formula of the other reagent.
Give the colour change that occurs during the reaction. from to
Draw the displayed formula for methanol and for methanoic acid in the boxes. methanol methanoic acid
Methanol reacts with methanoic acid to form an ester. Complete the equation for this reaction. CH₃OH + HCOOH → +
The structural formula of an ester is CH₃COOCH₂CH₂CH₂CH₃
What is the name of this ester?
Choose your answer
butyl ethanoate
butyl methanoate
ethyl butanoate
methyl butanoate
Deduce the molecular formula of this ester.
A scientist reacts lead(II) nitrate solution with sodium bromide solution. This is the equation for the reaction. Pb(NO₃)₂(aq) + 2NaBr(aq) → PbBr₂(s) + 2NaNO₃(aq)
Describe how the scientist could obtain a pure dry sample of lead(II) bromide (PbBr₂) from the reaction mixture.
The scientist reacts an excess of lead(II) nitrate solution with 25 cm³ of sodium bromide solution of concentration 2.0 mol/dm³.
Show that the amount of sodium bromide used is 0.050 mol.
Show that the maximum theoretical mass of lead(II) bromide is approximately 9 g. [for PbBr₂ Mr = 367]
The scientist electrolyses molten lead(II) bromide using this apparatus. +– positive electrode negative electrode molten lead(II) bromide crucible
Explain why lead(II) bromide needs to be molten rather than solid for electrolysis to occur.
The electrolyte is at a temperature of 400 °C. Explain a suitable material for the electrodes.
Give the half‑equation that occurs at the negative electrode.
Bromine forms at the positive electrode. This is the half‑equation for the reaction at the positive electrode. 2Br⁻ → Br₂ + 2e–
State what is observed at the positive electrode.
State why the half‑equation represents an oxidation reaction.
This question is about hydrogen chloride (HCl). Hydrogen chloride is a covalent compound.
State, in terms of electrostatic attraction, what is meant by a covalent bond.
When hydrogen chloride gas is dissolved in an organic solvent, the hydrogen chloride remains a covalent molecule. When hydrogen chloride gas is dissolved in water, ions are formed. Explain what happens when dry blue litmus paper is dipped into separate samples of each solution.
In the presence of ultraviolet radiation, hydrogen reacts with chlorine to form hydrogen chloride. This is the equation for the reaction. H₂(g) + Cl₂(g) → 2HCl(g) The table shows the bond energies. Bond H H Cl Cl H Cl Bond energy in kJ/mol 436 242 431
Calculate the enthalpy change (ΔH), in kJ/mol, for the reaction. Include a sign in your answer. ΔH = kJ/mol
Draw a reaction profile for the reaction. Label the reactants, the products, ΔH and the activation energy (Ea ). energy