Question
A list of substances is shown.
ammonium nitrate
carbon monoxide
copper(II) chloride
ethane
ethene
litmus
methane
methyl orange
sodium chloride
sodium sulfate
sulfur dioxide
thymolphthalein
Answer the following questions using only the substances from the list.
Each substance may be used once, more than once or not at all.
Give the name of the substance that:
(a) turns from blue to colourless when an acid is added……………………………………………………………………………………………………………………………. [1]
(b) is in many fertilisers……………………………………………………………………………………………………………………………. [1]
(c) is a salt which has a negative ion with a charge of 2–……………………………………………………………………………………………………………………………. [1]
(d) is a waste gas from digestion in animals……………………………………………………………………………………………………………………………. [1]
(e) is a hydrocarbon with a total of five atoms in a molecule……………………………………………………………………………………………………………………………. [1]
(f) is a compound of a transition element…………………………………………………………………………………………………………………………….. [1] [Total: 6]
▶️Answer/Explanation
Ans:
(a) thymolphthalein
(b) ammonium nitrate
(c) sodium sulfate
(d) methane
(e) methane
(f) copper(II) chloride
Question
(a) Fig. 2.1 shows the distillation apparatus that can be used to separate water from aqueous copper(II) sulfate.
Explain how distillation separates water from aqueous copper(II) sulfate.
(b) Fig. 2.2 shows a fractionating column for separating petroleum into different hydrocarbon fractions.
(i) On Fig. 2.2, draw an \(\mathbf{X}\) inside the column to show where the hydrocarbon with the highest viscosity collects. \([1]\)
(ii) Name the fraction labelled \(\mathbf{A}\) in Fig. 2.2. \([1]\)
(iii) State the name of the fraction in Fig. 2.2 which has the lowest boiling point. \([1]\)
(iv) State one use of the bitumen fraction. \([1]\) [Total: 6]
▶️Answer/Explanation
Ans:
(a) water evaporates / boils (but copper(II) sulfate does not) (1)
water condenses / turns to liquid in condenser (1)
(b)(i) X in lowest section of the fractionating column / X in the fractionating column where bitumen collects
(b)(ii) kerosene / paraffin
(b)(iii) refinery gas
(b)(iv) making roads
Question
(a) Table 3.1 shows the average concentrations, in \(\mathrm{ng} / 1000 \mathrm{~cm}^3\), of air pollutants in four different years.
(i) Name the pollutant that has the lowest concentration in 2019.\([1]\)
(ii) Name the pollutant that shows a continuous decrease in concentration from 2019 to 2022.[1]
(iii) Calculate the average mass, in \(\mathrm{ng}\), of sulfur dioxide in a \(250 \mathrm{~cm}^3\) sample of polluted air in 2020.
mass = ………………………… ng [1]
(b) (i) State one source of sulfur dioxide in the atmosphere………………………………………………………………………………………………………………………. [1]
(ii) State one adverse effect of sulfur dioxide in the atmosphere………………………………………………………………………………………………………………………. [1]
(iii) Choose the compound used to remove sulfur dioxide in flue gas desulfurisation.
(iv) Hydrochloric acid reacts with sodium sulfite.
The products are sodium chloride, sulfur dioxide and a liquid which turns anhydrous cobalt(II) chloride pink.
Complete the symbol equation for this reaction.
$
\mathrm{Na}_2 \mathrm{SO}_3+\ldots . \mathrm{HCl} \rightarrow 2 \mathrm{NaCl}+\mathrm{SO}_2+\ldots \ldots \ldots
$
(v) Name the acidified solution used to test for sulfur dioxide gas and state the observations. acidified solution
observations[2]
(c) Ammonia forms an alkaline solution in water.
(i) Give the formula of the ion that is present in all alkaline solutions.[1]
(ii) Choose from the list the \(\mathrm{pH}\) value for an alkaline solution.
Draw a circle around your chosen answer.
\(\begin{array}{llll}\mathrm{pH} 1 & \mathrm{pH} 4 & \mathrm{pH} 7 & \mathrm{pH} 13\end{array}\) [Total: 12]
▶️Answer/Explanation
Ans:
(a)(i) ammonia
(a)(ii) particulates
(a)(iii) 5.0 (ng)
(b)(i) combustion of fossil fuels
(b)(ii) acid rain / stated effect of acid rain
(b)(iii) 2nd box down ticked (calcium oxide)
(b)(iv) \(\begin{aligned} & \mathrm{H}_2 \mathrm{O}(1) \\ & 2(\mathrm{HCl})(1)\end{aligned}\)
(b)(v) (aqueous acidified) potassium manganate ((VII)) (1)
(c)(i) $
\mathrm{OH}^{-}
$
(c)(ii) \(\mathrm{pH} 13\)
turns colourless / decolourised (1)
Question
Bromine is a liquid at room temperature.
(a) State two general properties of a liquid.
1 ……………………………………………………………………………………………………………………………….
2 ……………………………………………………………………………………………………………………………….[2]
(b) Fig. 4.1 shows the physical states of bromine.
Name the changes of physical states A and B.
A ………………………………………………………………………………………………………………………………
B ………………………………………………………………………………………………………………………………[2]
(c) Describe liquid bromine and bromine gas in terms of the arrangement and motion of the
particles.
liquid bromine
arrangement ……………………………………………………………………………………………………………….
motion ……………………………………………………………………………………………………………………….
bromine gas
arrangement ………………………………………………………………………………………………………………
motion ……………………………………………………………………………………………………………………….[4]
(d) A sealed gas syringe contains \(80 \mathrm{~cm}^3\) of bromine gas.
State how decreasing the pressure affects the volume of bromine gas in the gas syringe when the temperature remains constant. [1] [Total: 9]
▶️Answer/Explanation
Ans:
mark each for any two of:
• has a definite volume / fixed volume
• takes the shape of its container
• flows over a surface / can be poured over a surface
(b) A: freezing (1)
B: evaporation / boiling (1)
(c) liquid bromine:
arrangement: irregular / no (particular) arrangement (1)
motion: sliding / moving (over each other) (1)
bromine gas:
arrangement: irregular / no (particular) arrangement (1)
motion: fast / rapid / move everywhere (1)
(d) volume increases
Question
This question is about metals and metal compounds.
(a) Table 5.1 shows some properties of some Group I metals.
Use the information in Table 5.1 to predict:
(i) the melting point of rubidium ……………………………………………………………………………. [1]
(ii) the solubility of sodium hydroxide at room temperature ……………………………………….. [1]
(iii) the observations when potassium reacts with water……………………………………………………………………………………………………………………… [1]
(iv) the physical state of caesium at 20°C. Give a reason for your answer.
physical state ……………………………………………………………………………………………………….
reason ………………………………………………………………………………………………………………………………………………………………………………………………………………………………………… [2]
(b) Iron is extracted in a blast furnace by reduction of iron(III) oxide, \(\mathrm{Fe}_2 \mathrm{O}_3\), with carbon monoxide.
Carbon monoxide is produced by the reaction of carbon with carbon dioxide.
$
\mathrm{C}+\mathrm{CO}_2 \rightarrow 2 \mathrm{CO}
$
(i) Explain how this equation shows that carbon dioxide is reduced.\([1]\)
(ii) Name the type of chemical reaction where oxidation and reduction take place simultaneously.\([1]\)
(iii) Calcium carbonate is added to the blast furnace.
The calcium carbonate undergoes thermal decomposition.
State the meaning of the term thermal decomposition.[2]
(c) Stainless steel is an alloy of iron.
(i) Give one reason why alloys are more useful than pure metals.
(ii) Brass is an alloy.
Choose the diagram, A, B, C or D, in Fig. 5.1 that best shows the structure of brass.
diagram …………………………………………………………………………………………………………. [1]
(d) Table 5.2 gives some observations about the reactivity of four metals with dilute hydrochloric acid.
Put the four metals in order of their reactivity.
Put the least reactive metal first.
▶️Answer/Explanation
Ans:
(a)(i) values between 30 and 62 (°C) (inclusive of these values) 1
(a)(ii) values between 100 and 1100 \(\left(\mathrm{g} / \mathrm{dm}^3\right)\) (inclusive of these values) 1
(a)(iii) bubbles form rapidly AND flame
OR
bubbles form very rapidly
(a)(iv) solid (1)
20 °C is below the melting point / the melting point is above 20 °C (1)
(b)(i) \(\mathrm{CO}_2\) loses oxygen
(b)(ii) redox
breakdown of a compound (1)
by heating / using heat / high temperature (1)
(c)(i) stronger / harder / more resistant to corrosion
(c)(ii) A
(d) mercury < tin < iron < magnesium (2)
1 mark if one pair reversed
Question
A student investigates the reaction of large pieces of magnesium carbonate with dilute
hydrochloric acid at 20°C. The magnesium carbonate is in excess.
(a) Fig. 6.1 shows the volume of carbon dioxide gas released as the reaction proceeds.
(i) Deduce the volume of carbon dioxide gas released after 2 minutes.
volume of carbon dioxide \(=\) \(\mathrm{cm}^3[1]\)
(ii) The student repeats the experiment using the same volume of hydrochloric acid but with a higher concentration. The magnesium carbonate is still in excess.
All other conditions stay the same.
Draw a line on the grid in Fig. 6.1 to show the volume of carbon dioxide released when hydrochloric acid with a higher concentration is used. [2]
(b) (i) The student repeats the experiment using smaller pieces of magnesium carbonate.
All other conditions stay the same.
Describe how the rate of reaction differs when smaller pieces of magnesium carbonate are used.\([1]\)
(ii) The student repeats the experiment at \(10^{\circ} \mathrm{C}\).
All other conditions stay the same.
Describe how the rate of reaction differs when the temperature is \(10^{\circ} \mathrm{C}\).\([1]\)
(c) Hydrochloric acid reacts with iron.
Complete the word equation for this reaction.
(d) Acids are used as catalysts in many chemical reactions.
State the meaning of the term catalyst. [2] [Total: 9]
▶️Answer/Explanation
Ans:(a)(i) \(29 \mathrm{~cm}^3\)
(a)(ii) steeper initial gradient starting at \(0-0\) (1)
line levels off above \(42 \mathrm{~cm}^3\) (1)
(b)(i) rate faster / rate increases / reaction speeds up
(b)(ii) rate slower / rate decreases
(c) iron(II) chloride / iron chloride (1)
hydrogen (1)
(d) substance that increases the rate of reaction (1)
and is unchanged (at the end of the reaction) (1)
Question
(a) Fig. 7.1 shows the displayed formula of compound S.
(i) On Fig. 7.1, draw a circle around the carboxylic acid functional group.[1]
(ii) Deduce the molecular formula of compound \(\mathbf{S}\).[1]
(b) Compound \(\mathbf{S}\) can be converted to acrylic acid. The molecular formula of acrylic acid is \(\mathrm{C}_3 \mathrm{H}_4 \mathrm{O}_2\).
(i) Complete Table 7.1 to calculate the relative molecular mass of acrylic acid.
relative molecular mass = ………………………… [2]
(ii) Acrylic acid is an unsaturated compound.
Describe a test for an unsaturated compound.
test ……………………………………………………………………………………………………………………..
observations ……………………………………………………………………………………………………….. [2]
(iii) When left in the air, acrylic acid forms a polymer.
State the meaning of the term polymer………………………………………………………………………………………………………………………. [2]
(iv) Poly(ethene) is also a polymer.
Choose from the list the type of polymerisation that occurs when poly(ethene) is made.
Draw a circle around your chosen answer.
substitution oxidation neutralisation addition [1]
(c) Ethanoic acid is a carboxylic acid.
Complete the word equation for the reaction of ethanoic acid with sodium hydroxide.
(d) Ethanoic acid can be converted to ethanol.
Name the two products formed when ethanol undergoes complete combustion.
…………………………………………………………. and …………………………………………………………. [2] [Total: 13]
▶️Answer/Explanation
Ans:
(a)(i) circle around the COOH group
(a)(ii) \(\mathrm{C}_3 \mathrm{H}_6 \mathrm{O}_3\)
(b)(i) 72 (2)
If 2 marks not scored 1 mark for \(\mathrm{H}=(4 \times 1)=4\) OR O \(=(2 \times 16)=32\)
(b)(ii) add aqueous bromine (1)
decolourises / goes colourless (1)
(b)(iii) large molecule / long chain molecule (1)
formed form many small molecules / formed from monomers (1)
7(b)(iv) addition 1
7(c) sodium ethanoate (1)
water (1)
(d) carbon dioxide (1)
water (1)
Question
Lithium bromide is a compound with ionic bonding.
(a) State the meaning of the term ionic bond…………………………………………………………………………………………………………………………….. [2]
(b) Complete Fig. 8.1 to show:
● the electronic configuration of a lithium ion
● the charge on the ion.
(c) Deduce the number of protons and neutrons in the bromide ion shown.
$
{ }_{35}^{79} \mathrm{Br}^{-}
$
number of protons
number of neutrons\([2]\)
(d) Molten lithium bromide is electrolysed using graphite electrodes.
State the names of the product at each electrode and give the observations at the positive electrode.
product at the negative electrode
product at the positive electrode
observations at the positive electrode[3]
(e) Fig. 8.2 shows the structure of graphite.
(e) Fig. 8.2 shows the structure of graphite.
(i) State the type of bonding in graphite………………………………………………………………………………………………………………………. [1]
(ii) Explain by referring to Fig. 8.2 why graphite is used as a lubricant………………………………………………………………………………………………………………………. [1]
(iii) Graphite and diamond are both forms of carbon.
State one use of diamond………………………………………………………………………………………………………………………. [1] [Total: 12]
▶️Answer/Explanation
Ans:
(a) (strong) electrostatic attraction (1)
between oppositely charged ions (1)
(b) 2 electrons in shell of Li only (1)
+ / 1+ charge outside brackets (1)
8(c) protons: 35 (1)
electrons: 44 (1)
8(d) negative electrode: lithium (1)
positive electrode: bromine (1)
observations: red-brown vapour (1)
(e)(i) covalent (1)
(e)(ii) the layers can slide over each other / the layers can slip over each other 1
(e)(iii) cutting (tools)