Separate Chemistry 2Edexcel GCSE Chemistry: Topic test

20 questions, 54 marks

Edexcel GCSE Chemistry

Separate Chemistry 2 topic test

Total 54 marks

Name

Class

Date

1
A technician is investigating a white solid ionic compound, Y, that she knows contains an ammonium ion and one other metal ion. She mixes a sample of Y with dilute sodium hydroxide solution and warms the mixture gently, holding a piece of damp red litmus paper near the mouth of the test tube; the paper turns blue. She then moistens a second sample of Y and holds it in a blue Bunsen flame on a clean nichrome wire, observing a lilac flame colour.
(a)
What does the result of warming compound Y with sodium hydroxide solution show?
[1 mark]
AA gas is produced that turns damp red litmus paper blue, confirming the ammonium ion is present
BA white precipitate forms, confirming the ammonium ion is present
CA gas is produced that turns limewater milky, confirming the carbonate ion is present
DNo visible change occurs, so no conclusion can be drawn about compound Y
(b)
What does the lilac flame colour observed with the second sample of Y show?
[1 mark]
AThe compound contains a sodium ion, Na+
BThe compound contains a potassium ion, K+
CThe compound contains a lithium ion, Li+
DThe compound contains a calcium ion, Ca2+
(c)
The technician wants to check whether compound Y also contains a sulfate ion. Describe a chemical test she could carry out on a solution of Y to test for this, and state the result that would confirm a sulfate ion is present.
[2 marks]
Total for question 1: 4 marks
2
A camping-gas cylinder is labelled as containing pure butane, C4H10. A technician ignites a jet of the gas so that it burns in a plentiful supply of air. She holds a cold glass beaker above the blue flame and sees a colourless liquid condense on the inside of the beaker. She then directs the waste gases from the flame through a test tube of limewater, which turns milky.
(a)
Butane has the molecular formula C4H10. Which statement correctly explains why butane is classified as a saturated hydrocarbon?
[1 mark]
AEvery carbon-carbon bond in the molecule is a single covalent bond, so no more hydrogen atoms could be added
BButane is a gas at room temperature, which is true of all saturated hydrocarbons
CButane molecules contain a carbon-carbon double bond, C=C, which cannot react further
DButane reacts rapidly with bromine water, decolourising it
(b)
The colourless liquid condensing in the cold beaker, together with the milky colour change of the limewater, provide evidence for which two products of the complete combustion of butane?
[1 mark]
ACarbon dioxide and carbon monoxide
BSoot (carbon) and oxygen
CHydrogen gas and carbon dioxide
DCarbon dioxide and water
(c)
Write a balanced symbol equation for the complete combustion of butane, C4H10, in an excess of oxygen.
[2 marks]
Total for question 2: 4 marks
3
A manufacturer produces plastic pipes from poly(chloroethene), commonly known as PVC, made by polymerising chloroethene monomers of structure CH2=CHCl, each containing one carbon-carbon double bond. A different manufacturer produces a non-stick coating for cooking pans from poly(tetrafluoroethene) (PTFE), whose repeating unit is -CF2-CF2-.
(a)
Describe how chloroethene monomers, CH2=CHCl, join together in an addition polymerisation reaction to form poly(chloroethene), referring to what happens to the carbon-carbon double bond.
[3 marks]
(b)
Deduce the structural formula of the monomer used to make PTFE, whose repeating unit is -CF2-CF2-, and explain one property of PTFE that makes it suitable for use as a non-stick coating on cooking pans, linking this property to the structure of the polymer.
[4 marks]
Total for question 3: 7 marks
4
A student has a sample of ethanol, C2H5OH. She knows that ethanol can be produced by fermenting glucose solution using yeast, that a concentrated solution of ethanol can then be obtained from the resulting mixture, and that ethanol can also be dehydrated to form an alkene.
(a)
Describe fully how a concentrated solution of ethanol is obtained starting from glucose solution, including the fermentation process and how the ethanol produced is then concentrated.
[6 marks]
(b)
The student then dehydrates a separate sample of ethanol to form an alkene. State the name and formula of the alkene formed, explain what type of reaction dehydration is, and describe a chemical test, including the expected observation, that would show the product is this alkene rather than unreacted ethanol.
[6 marks]
Total for question 4: 12 marks
5
A company is developing a catalyst for use in a chemical reaction. They compare two forms of the same metal: form P consists of large metal pellets, and form Q consists of the same total mass of metal broken down into nanoparticles, giving form Q a much greater total surface area than form P for the same mass of metal.
(a)
Why does the reaction proceed faster when form Q (nanoparticles) is used as the catalyst instead of form P (large pellets)?
[1 mark]
ANanoparticles have a lower surface area to volume ratio than large pellets, slowing the reaction
BNanoparticles have a different chemical formula from the same metal in bulk form
CNanoparticles have a much higher surface area to volume ratio than large pellets, exposing more particles at the surface where the reaction can take place
DNanoparticles are magnetic, which increases the rate of all chemical reactions
(b)
The particles that make up form Q are correctly described as nanoparticles because they have a diameter within which of these ranges?
[1 mark]
A1-100 micrometres
B1-100 millimetres
C1-100 picometres
D1-100 nanometres
(c)
State one possible risk of using nanoparticles such as form Q in industrial or consumer products, and explain why this risk arises from their very small size.
[2 marks]
Total for question 5: 4 marks
6
A student is given a colourless solution of an unknown salt, Z. She first adds a few drops of dilute hydrochloric acid to a sample of Z and observes vigorous effervescence, with the gas produced turning limewater milky when bubbled through it. She then takes a second, separate sample of solution Z, adds dilute nitric acid followed by silver nitrate solution, and observes a cream-coloured precipitate forming.
(a)
Which anion is confirmed to be present in solution Z by the effervescence with dilute hydrochloric acid and the milky limewater?
[1 mark]
ASulfate ion, SO4^2-
BChloride ion, Cl-
CCarbonate ion, CO3^2-
DNitrate ion, NO3-
(b)
The cream-coloured precipitate formed when acidified silver nitrate solution is added to solution Z confirms the presence of which halide ion?
[1 mark]
AChloride ion, Cl- (white precipitate)
BBromide ion, Br- (cream precipitate)
CIodide ion, I- (yellow precipitate)
DFluoride ion, F- (no precipitate)
(c)
Suggest why the student added dilute nitric acid to the sample of solution Z before adding silver nitrate solution in the halide test, rather than adding silver nitrate solution on its own.
[2 marks]
Total for question 6: 4 marks
7
A food scientist investigates a sample of vinegar, a dilute aqueous solution of ethanoic acid, CH3COOH. She adds a small volume of the vinegar to a test tube containing solid sodium carbonate and observes vigorous effervescence. She also compares the structure of ethanoic acid with that of methanoic acid, HCOOH, the simplest member of the same homologous series.
(a)
Describe the structure of a molecule of ethanoic acid, CH3COOH, stating how many carbon, hydrogen and oxygen atoms it contains, and identifying its functional group.
[3 marks]
(b)
State the gas produced when the vinegar reacts with solid sodium carbonate, give a balanced symbol equation for the reaction between ethanoic acid and sodium carbonate, and explain, in terms of functional groups, why methanoic acid would be expected to react with sodium carbonate in the same way.
[4 marks]
Total for question 7: 7 marks
8
A packaging company is choosing a material to make disposable food containers. They compare data for four candidate materials. Poly(ethene): density 0.94 g/cm3, softens at 115 degrees Celsius, flexible, non-biodegradable. Poly(propene): density 0.90 g/cm3, softens at 160 degrees Celsius, more rigid, non-biodegradable. A starch-based biodegradable polymer: density 1.3 g/cm3, softens at 60 degrees Celsius, broken down by microorganisms within weeks. Glass: density 2.5 g/cm3, softens at 550 degrees Celsius, does not degrade, heavy, can shatter.
(a)
Using the data given, evaluate which of the four materials would be most suitable for making a lightweight, disposable food container intended to be used once and then composted, and which would be least suitable, justifying your answer using the properties described.
[6 marks]
(b)
The company decides not to use poly(propene) or poly(ethene), despite their higher softening points than the starch-based polymer, because both are non-biodegradable. Explain, in terms of their structure, why poly(ethene) and poly(propene) do not biodegrade like the starch-based polymer, and describe one method, other than composting, that could be used to dispose of poly(ethene) and poly(propene) waste responsibly, giving one advantage and one disadvantage of this method.
[6 marks]
Total for question 8: 12 marks

End of questions