13246.02 MV18

Double Award Science:ChemistryUnit C1Higher Tier

[GDW22]TUESDAY 24 NOVEMBER 2020, MORNING

General Certificate of Secondary Education2020–2021

Time1 hour, plus your additional time allowance.

Instructions to CandidatesWrite your Centre Number and Candidate Number in the spaces provided at the top of this page.You must answer the questions in the spaces provided.Do not write on blank pages.Complete in black ink only. Answer all eight questions.

Information for CandidatesThe total mark for this paper is 70.Figures in brackets printed at the end of each question indicate the marks awarded to each question or part question.Quality of written communication will be assessed in Question 7.A Data Leaflet, which includes a Periodic Table of the elements is provided.

Centre Number

Candidate Number

MV18

13246.02 MV18 2

1 A paper chromatography experiment was carried out using three pure dyes (A, B and C) and three mixtures of dyes (1, 2 and 3). The chromatogram obtained is shown below. The solvent front and pencil line Z were drawn on

the chromatogram.

3A

3B

3C

31

32

33

solvent front

pencil lineZ 1

23

45

67

89

Cen

timet

res

spot X

(a) What name is given to the pencil line Z? [1 mark]

(b) Which one of the mixture of dyes (1, 2 or 3) does not contain dye A? [1 mark]

(c) Which one of the pure dyes (A, B or C) is most soluble in the solvent used? Explain your answer. [2 marks]

13246.02 MV18 3 [Turn over

(d) Using the ruler shown in the diagram opposite, determine the distance, in cm, moved by the solvent and by spot X from pencil line Z. [2 marks]

solvent cm

spot X cm

(e) Calculate the Rf value of spot X. Give your answer to 2 decimal places. [1 mark]

Rf =

13246.02 MV18 4

2 The Periodic Table contains all known elements.

(a) The melting points and boiling points of four elementslabelled A, B, C and D are shown in the table below.

Element Melting point/°C Boiling point/°C

A 63 759

B –101 –34

C –39 357

D 842 1484

(i) Which one of the elements (A, B, C, D) is a liquid atroom temperature (20 °C)? [1 mark]

(ii) Which one of the elements (A, B, C, D) could bepotassium? [1 mark]

(b) Lithium is found in Group 1 of the Periodic Table.

(i) Write a balanced symbol equation for the reaction oflithium with water. [3 marks]

13246.02 MV18 5 [Turn over

(ii) Complete the sentences below by circling the correct option in each box. [3 marks]

Compared to potassium, lithium is

more

less

equally

reactive.

Lithium and potassium are

alkali metals.

alkaline earth metals.

transition metals.

The reactivity of elements depends on the

inner shell electrons.

outer shell electrons.

total number of electrons.

(c) Explain why lithium and the other elements in Group 1 react in a similar way with water. [2 marks]

13246.02 MV18 6

3 (a) Potassium hydroxide reacts with carbon dioxide gas forming potassium carbonate and water.

Write a balanced symbol equation for this reaction. [3 marks]

(b) Potassium hydroxide solution reacts with hydrochloric acid forming potassium chloride and water.

(i) Which two of the terms below apply to the reaction between potassium hydroxide solution and hydrochloric acid? Circle both the correct answers.

[2 marks]

displacement

reduction

exothermic

endothermic

neutralisation

oxidation

(ii) Write an ionic equation for the reaction between potassium hydroxide and hydrochloric acid. Include state symbols. [3 marks]

13246.02 MV18 7 [Turn over

Blank page

(Questions continue overleaf)

13246.02 MV18 8

4 (a) Some magnesium powder was added to a beaker of dilute nitric acid as shown in the diagram below.

spatulamagnesium powder

dilute nitric acid

beaker

spatula

beaker

dilute nitric acid

magnesium powder

(i) Describe three observations that you would expectwhen magnesium powder is added to dilutenitric acid. [3 marks]

1.

2.

3.

(ii) What is the formula for the salt formed in thisreaction? [1 mark]

13246.02 MV18 9 [Turn over

(b) A technician made up four different solutions of hydrochloric acid by measuring varying amounts of 1.0 mol/dm3 hydrochloric acid and water into four different beakers A, B, C and D.

The composition of each of the solutions is recorded in the table.

BeakerVolume/cm3

water hydrochloric acid total

A 10.0 40.0 50.0

B 30.0 20.0 50.0

C 40.0 10.0 50.0

D 40.0 60.0 100.0

(i) Which beaker A, B, C or D contains the solution with the lowest pH? [2 marks]Explain your answer

Beaker:

Explanation:

(ii) Hydrochloric acid is a strong acid. Explain fully, in terms of particles, why hydrochloric

acid is described both as strong and as an acid. [2 marks]

13246.02 MV18 10

5 (a) Racing car wheels are often made from an alloy known as AZ70.

Complete the definition of an alloy: [2 marks]

An alloy is

(b) The six diagrams below show the bonding in different molecules. In each case the symbol for one of the atoms has been replaced with the letter X.

H

X HH

H

Diagram 1

H

H

H

H

X HH

Diagram 2

X Cl

Diagram 3

H

X HH

Diagram 4

X HH

Diagram 5Cl

X ClCl

Cl

Diagram 6

In how many of the diagrams could the letter X represent carbon? [1 mark]

13246.02 MV18 11 [Turn over

(c) Some properties of five different substances are given in the table below.

Complete the table by filling in all the blank spaces. [5 marks]

type

of

stru

ctur

esu

bsta

nce

mel

ting

poin

t/°C

boili

ng

poin

t/°C

solu

bilit

y in

wat

er

elec

tric

al

cond

uctiv

ity

solid

liqui

d

brom

ine

–759

low

poor

pota

ssiu

m

chlo

ride

770

1420

high

poor

good

copp

er10

8525

62go

odgo

od

gian

t io

nic

lithi

um

nitra

te25

560

0hi

ghgo

od

grap

hite

3600

low

good

good

13246.02 MV18 12

6 (a) Magnesium reacts with fluorine to form the compound magnesium fluoride.

(i) Complete the diagrams below to show the electronconfiguration in a magnesium atom and in a fluorineatom. All electrons should be shown. [2 marks]

magnesium atom fl uorine atom

(ii) Explain, in terms of the electrons involved, howatoms of magnesium and fluorine react to form thecompound magnesium fluoride. [4 marks]

13246.02 MV18 13 [Turn over

(b) Water and oxygen are covalently bonded molecules.

In the spaces below draw dot and cross diagrams to show the bonding in water (H2O) and in oxygen (O2). Only outer electrons are needed. [5 marks]

water

oxygen

13246.02 MV18 14

(c) A covalent bond can be represented as a line, for example H—H.

Complete the table below, using a line or lines, to show covalent bonding in a molecule of nitrogen.

[1 mark]

molecule covalent bonding

hydrogen H—H

nitrogen

13246.02 MV18 15 [Turn over

Blank page

(Questions continue overleaf)

13246.02 MV18 16

7 Describe, in words, the structure of P3–, an ion of phosphorus which has a mass number of 31. You may find your Data Leaflet helpful. [6 marks]

In your answer you should:

give the name and number of each type of subatomicparticle present in a P3– ion

give the electronic configuration of a P3– ion, suggest aname for the P3– ion and name the element which hasthe same electronic configuration as a P3– ion

explain, by referring to its subatomic particles, why P3–

cannot be described as an atom, and give the chemicalterm used to describe ions such as P3–, O2–

and F–.

In this question you will be assessed on yourwritten communication skills including the use ofspecialist scientific terms.

the name and number of each type of subatomic particlepresent in a P3– ion

13246.02 MV18 17 [Turn over

the electronic configuration of a P3– ion, suggest a name for the P3– ion and name the element which has the same electronic configuration as a P3– ion

explain, by referring to its subatomic particles, why P3–

cannot be described as an atom, and give the chemical term used to describe ions such as P3–, O2– and F–

13246.02 MV18 18

8 (a) Calculate the relative formula mass (Mr) of the following compounds: [1 mark for each]

(relative atomic masses: H = 1, C = 12, O = 16, Mg = 24, Ca = 40)

magnesium hydroxide Mg(OH)2

calcium hydrogencarbonate Ca(HCO3)2

(b) Magnesium sulfate, MgSO4, has a relative formula mass (Mr) of 120.

(i) Calculate the number of moles in 55 g of magnesium sulfate. Give your answer to 2 decimal places.

[2 marks]

13246.02 MV18 19 [Turn over

(ii) Calculate the mass of 0.125 moles of magnesiumsulfate. [1 mark]

g

13246.02 MV18 20

(c) Sodium hydroxide reacts with iron(III) nitrate to form iron(III) hydroxide and sodium nitrate. The equation for the reaction is:

3NaOH + Fe(NO3)3 → Fe(OH)3 + 3NaNO3

The table below gives the relative formula masses (Mr) of the reactants and products.

Substance Relative formula mass (Mr)

sodium hydroxide NaOH 40

iron(lll) nitrate Fe(NO3)3 242

iron(lll) hydroxide Fe(OH)3 107

sodium nitrate NaNO3 85

13246.02 MV18 21 [Turn over

(i) Calculate the maximum mass of iron(III) hydroxide which could be obtained when 7.2 g of sodium hydroxide in solution reacts with excess

iron(III) nitrate. [3 marks]

mass of Fe(OH)3 = g

13246.02 MV18 22

(ii) When the reaction was carried out, 5.45 g of iron(III) hydroxide were obtained. Using your answer to (c) (i), calculate the percentage yield. [2 marks]Give your answer to 1 decimal place.

percentage yield = %

(iii) The reactants used were pure and no iron(III) hydroxide was lost during separation. Suggest one reason why the percentage yield was less than 100 %. [1 mark]

This is the end of the question paper

Permission to reproduce all copyright material has been applied for.In some cases, efforts to contact copyright holders may have been unsuccessful and CCEAwill be happy to rectify any omissions of acknowledgement in future if notifi ed.

Examiner Number

For Examiner’suse only

QuestionNumber Marks

1 2 3 4 5 6 7 8

TotalMarks

13246.02 MV18

Sources

Q5(a).... © Getty Images

© CCEA 2017

SYMBOLS OF SELECTED IONS

SOLUBILITY IN COLD WATER OF COMMON SALTS, HYDROXIDES AND OXIDES

Negative ions

SolubleAll sodium, potassium and ammonium saltsAll nitratesMost chlorides, bromides and iodidesEXCEPT silver and lead chlorides, bromides and iodidesMost sulfates EXCEPT lead and barium sulfatesCalcium sulfate is slightly soluble

InsolubleMost carbonates EXCEPT sodium, potassium and ammonium carbonatesMost hydroxidesEXCEPT sodium, potassium and ammonium hydroxidesMost oxidesEXCEPT sodium, potassium and calcium oxides which react with water

Name Symbol

Ammonium

Chromium(III) Cr3+

Copper(II) Cu2+

Iron(II) Fe2+

Iron(III) Fe3+

Lead(II) Pb2+

Silver Ag+

Zinc Zn2+

Name SymbolButanoate C3H7COO-

CarbonateDichromateEthanoate CH3COO-

HydrogencarbonateHydroxide OH–

Methanoate HCOO–

Nitrate NOPropanoate C2H5COO–

SulfateSulfi te

NewSpe

cifi ca

tion

Positive ions

© CCEA 2017

For fi rst teaching from September 2017

Data Leafl etIncluding the Periodic Table of the Elements

For the use of candidates takingScience: Chemistry,

Science: Double Awardor Science: Single Award

Copies must be free from notes or additions of anykind. No other type of data booklet or information

sheet is authorised for use in the examinations

gcse examinations

chemistry

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89

139

57

256

101

223

87

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88

261

104

262

105

266

106

264

107

277

108

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271

110

272

111

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* 58 – 71 Lanthanum series† 90 – 103 Actinium series

a = relative atomic mass

x = atomic symbolb = atomic number

THE PERIODIC TABLE OF ELEMENTSGroup

a

bx

*

†

1

11 2 3 4 5 6 7

0

285

112Copernicium

(approx)