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(a) A list of formulae is shown.
CaCO$_3$
CaO
Cl$_2$
CH$_4$
C$_2$H$_5$OH
C$_2$H$_6$
CuSO$_4$
H$_2$
H$_2$O
MgO
NaCl
SO$_2$
Answer the following questions using these formulae. Each formula may be used once, more than once or not at all. State which formula represents:
(i) a compound that is the main constituent of natural gas
................................................................................................................. [1]
(ii) an element that is used in water treatment
................................................................................................................. [1]
(iii) an element that bleaches damp litmus paper
................................................................................................................. [1]
(iv) a compound that contains an ion with a single negative charge
................................................................................................................. [1]
(v) a hydrocarbon that is formed by the decomposition of vegetation.
................................................................................................................. [1]
(b) Complete the dot-and-cross diagram to show the electron arrangement in a molecule of water. [2]
(c) State whether calcium oxide is a basic oxide or an acidic oxide. Give a reason for your answer.
.................................................................................................................
................................................................................................................. [1]
511
557
555
The table shows the masses of some of the ions in 1000 cm$^3$ of water taken from a lake.
[Table]
(a) Answer these questions using only the information in the table.
(i) State which of the negative ions has the lowest concentration.
..................................................................................................................................... [1]
(ii) Name the compound containing Na$^+$ and NO$_3^-$ ions.
..................................................................................................................................... [1]
(iii) Calculate the mass of chloride ions in 250 cm$^3$ of lake water.
mass = .............................. mg [1]
(b) Describe a test for sulfate ions.
test ................................................................................................................................
observations .................................................................................................................... [2]
(c) Citric acid is also present in the lake water.
The structure of citric acid is shown.
(i) Deduce the number of carboxylic acid groups in one molecule of citric acid.
..................................................................................................................................... [1]
(ii) The formula of citric acid is C$_6$H$_8$O$_7$.
Complete the table to calculate the relative molecular mass of citric acid.
[Table_2]
relative molecular mass = .......................... [2]
[Total: 8]
514
577
576
(a) Name an ore of iron.
(b) (i) Complete the chemical equation for the reduction of iron(III) oxide in the blast furnace.
$\text{Fe}_2\text{O}_3 + .....\text{CO} \rightarrow .....\text{Fe} + 3\text{CO}_2$
(ii) State the meaning of the term \textit{reduction}.
(c) Calcium carbonate (limestone) is added to the blast furnace. The calcium carbonate undergoes thermal decomposition. State the meaning of the term \textit{thermal decomposition}.
(d) Iron can be made into stainless steel.
(i) Give one use of stainless steel.
(ii) Describe one advantage of stainless steel compared with pure iron.
(e) The symbol for an isotope of iron is shown.
$$\begin{align} ^{57}_{26}\text{Fe} \end{align}$$
Deduce the number of electrons, neutrons and protons in one atom of this isotope of iron.
number of electrons
number of neutrons
number of protons
(f) Iron is a good conductor of heat and electricity. Give two \textit{other} physical properties of iron that are characteristic of all metals.
1
2
(g) Iron rusts. Name the \textit{two} substances needed for iron to rust.
1
2
546
600
541
The table shows some properties of the Group I elements.
[Table_1]
(a) (i) Complete the table by predicting:
• the melting point of potassium
• the density of francium. [2]
(ii) Describe the observations when lithium reacts with water.
..............................................................................................................................
.............................................................................................................................. [1]
(b) (i) Deduce the electronic structure of sodium.
Use the Periodic Table to help you.
.............................................................................................................................. [1]
(ii) Explain why a potassium ion has a single positive charge.
..............................................................................................................................
.............................................................................................................................. [1]
(c) Sodium reacts with water to produce aqueous sodium hydroxide and a gas which ‘pops’ with a lighted splint.
(i) Complete the chemical equation for this reaction.
$$2\text{Na} + 2\text{H}_2\text{O} \rightarrow .....\text{NaOH} + ..........$$ [2]
(ii) Choose one value from the list that best describes the pH of aqueous sodium hydroxide.
Draw a circle around the correct answer.
pH 1 pH 4 pH 7 pH 14 [1]
513
570
521
The table shows the structures of some organic compounds.
(a) Complete the table by naming the homologous series. The first one has been done for you. [2]
(b) Draw the structure of a compound containing two carbon atoms which belongs to the same homologous series as compound H. Show all of the atoms and all of the bonds. [1]
(c) Describe the colour change when an excess of compound J is added to aqueous bromine.
from ............................................................ to ............................................................ [2]
(d) (i) Compound J can be obtained by cracking petroleum fractions. State the conditions needed for cracking.
..........................................................................................................................
.......................................................................................................................... [2]
(ii) Complete this sentence about cracking using a word from the list: bitumen hydrogen oxygen petroleum.
The chemicals manufactured by cracking include alkanes, alkenes and ............................ . [1]
(e) Compound G is propane. Complete the word equation for the complete combustion of propane.
[Table_1]
propane + oxygen → ............................ + ............................ [2]
(f) Compound J can form polymers.
(i) State the meaning of the term polymer.
..........................................................................................................................
.......................................................................................................................... [2]
(ii) Nylon is also a polymer. Give one use of nylon.
.......................................................................................................................... [1]
(iii) Describe one pollution problem caused by non-biodegradable plastics.
..........................................................................................................................
.......................................................................................................................... [1]
501
519
564
The diagrams show part of the structures of potassium iodide and bromine at room temperature and pressure.
(a) Describe the physical properties of these substances in terms of:
• volatility
potassium iodide .....................................................................................................................
bromine .................................................................................................................................
• solubility in water
potassium iodide .....................................................................................................................
bromine .................................................................................................................................
• electrical conductivity when molten (liquid).
potassium iodide .....................................................................................................................
bromine ................................................................................................................................. [5]
(b) Molten potassium iodide is electrolysed using carbon (graphite) electrodes.
(i) Name the substance produced at the positive electrode.
............................................................................................................................... [1]
(ii) Aqueous potassium iodide reacts with aqueous bromine.
Complete the word equation for this reaction.
potassium iodide + bromine → ....................... + ....................... [2]
(iii) Explain in terms of the reactivity of the halogens why aqueous potassium chloride does not react with aqueous bromine.
...............................................................................................................................
............................................................................................................................... [1]
(c) Name the change of state when liquid bromine changes to solid bromine.
............................................................................................................................... [1]
[Total: 10]
502
576
529
This question is about sulfur and compounds of sulfur.
(a) Use the kinetic particle theory to describe the differences between sulfur gas and solid sulfur in terms of:
• the arrangement of the particles
...............................................................
...............................................................
...............................................................
• the separation of the particles.
...............................................................
...............................................................
............................................................... [4]
(b) Give the major use of sulfur in industry.
.................................................................. [1]
(c) Sulfur dioxide is a pollutant in the air that contributes to acid rain.
(i) State one adverse effect of sulfur dioxide on health.
.................................................................. [1]
(ii) Name one other oxide that contributes to acid rain.
.................................................................. [1]
(iii) Sulfur dioxide reacts with water to produce sulfurous acid.
The reaction is reversible.
Draw the symbol for a reversible reaction in the box.
$$\text{SO}_2 + \text{H}_2\text{O} \square \text{H}_2\text{SO}_3$$ [1]
(d) The equation for the reaction of sodium sulfite with zinc is shown.
$$\text{Na}_2\text{SO}_3 + 3\text{Zn} \rightarrow \text{Na}_2\text{S} + 3\text{ZnO}$$
Explain how this equation shows that zinc is oxidised.
...............................................................
............................................................... [1]
518
530
501
A student investigated the reaction of small pieces of calcium carbonate with dilute hydrochloric acid. The hydrochloric acid was in excess.
$$\text{CaCO}_3 + 2\text{HCl} \rightarrow \text{CaCl}_2 + \text{CO}_2 + \text{H}_2\text{O}$$
The rate of reaction is found by measuring the decrease in the mass of the reaction mixture with time.
The results are shown on the graph.
(a) Deduce the time taken from the beginning of the experiment for the mass of the reaction mixture to decrease by 1.0 g.
time = ................................. s [1]
(b) The experiment was repeated using dilute hydrochloric acid of a higher concentration.
All other conditions stayed the same.
Draw a line on the grid to show how the mass of the reaction mixture changes with time using acid of a higher concentration. [2]
(c) Describe the effect each of the following has on the rate of reaction of calcium carbonate with hydrochloric acid.
All other conditions stay the same.
• The reaction is carried out at a higher temperature.
................................................................................................................
• The reaction is carried out using large pieces of calcium carbonate instead of small pieces of calcium carbonate.
................................................................................................................
[2]
(d) When 0.44 g of calcium carbonate is used, 100 $\text{cm}^3$ of carbon dioxide gas is formed.
Calculate the mass of calcium carbonate needed to produce 25 $\text{cm}^3$ of carbon dioxide gas.
mass of calcium carbonate = ............................. g [1]
(e) The table compares the reaction of four metals with dilute hydrochloric acid.
[Table_1]
Put the four metals in order of their reactivity.
Put the least reactive metal first.
least reactive __________________________________________ most reactive
[2]
[Total: 8]
540
594
537
