Types of Substance (Edexcel GCSE Chemistry)

Exam Questions

4 hours30 questions
1a1 mark

Chlorine, bromine and iodine are elements in group 7 of the periodic table.

Chlorine is toxic.

State one safety precaution that should be taken when using chlorine in the laboratory.

1b4 marks

Chlorine reacts with hydrogen to form hydrogen chloride.

i)
Write the word equation for this reaction.

............................................ → ............................................

(1)

ii)
Hydrogen chloride dissolves in water to form an acidic solution.
State what is seen when blue litmus paper is placed into this solution.
(1)
iii)
A chlorine atom has seven electrons in its outer shell.
A hydrogen atom has one electron in its outer shell.

Complete the dot and cross diagram of a molecule of hydrogen chloride.
Show outer shell electrons only.
(1)

fig-q5biii-1cho-2f-paper-1-nov-2020

iv)
Name the type of bonding in a molecule of hydrogen chloride.

(1)

1c1 mark

If chlorine solution is added to sodium bromide solution a reaction occurs.

chlorine + sodium bromide → sodium chloride + bromine

Give a reason why this reaction occurs.

1d2 marks

Figure 8 shows apparatus used to find out if a solution conducts electricity.

fig-8-q5d-1cho-2f-paper-1-nov-2020
Figure 8

Glucose solution and sodium chloride solution are tested.
Glucose is a typical simple molecular covalent compound.
Sodium chloride is an ionic compound.

i)
State what would happen to the lamp when glucose solution is tested.
(1)
ii)
State what would happen to the lamp when sodium chloride solution is tested.
(1)
1e2 marks

Figure 9 shows how the conductivity of one solution changes as its concentration increases.

fig-9-q5e-1cho-2f-paper-1-nov-2020
Figure 9

Describe how the conductivity of this solution changes as its concentration increases from 0 to 500 gdm-3.

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2a4 marks

Substances can be classified into different categories depending on their properties. 

The structures of five substances are represented below:

aqa-gcse-2-1e-tp4a-mixture-of-substances

Give one substance, A, B, C, D or E that:

 Is a metal

 

 Represents the structure of diamond

 

 Is soft and slippery

 

 Is a compound

 

2b1 mark

Which element are substances and E made from?

2c2 marks

Substance C is methane, CH4.

Tick () two boxes that are correct about this substance.

  It has weak intermolecular forces  
  It cannot conduct electricity  
  It has a high melting point  
  It can conduct electricity  
  It has a high boiling point  

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3a1 mark

Which of these properties does titanium have?

A

Low density

B

Low melting point

C

Shiny

D

Soluble in water

3b1 mark

Figure 1 shows the structure of titanium.

edx-1-5e-paper-2-q3b-metal-structure

Figure 1

What is X labelling?

3c1 mark

Use Figure 1 to explain why titanium can conduct electricity.

3d1 mark

Titanium is malleable.

Describe what this means.

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4a1 mark

Figure 1 shows the structure of diamond and graphite.

 edx-1-5e-paper-2-q4a-diamond-and-graphite

Figure 1

State one similarity between the structure of diamond and graphite.

4b1 mark

State one way the structure of graphite is different to the structure of diamond.

4c2 marks

Diamond is used as a cutting tool.

i)
State the property that makes it good at this job.
[1]
ii)
Explain why diamond has this property

[1]

4d1 mark

Which property do graphite and metals both have?

A

Good conductor of electricity

B

High density

C

Low boiling point

D

Malleable

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5a2 marks

Poly(ethene) is a plastic used to make objects like plastic bags.

Use the correct words from the box to complete the sentence:

monomers                    polymers

 

Plastics like poly(ethene) are  ………………… made up of linking together many small molecules called……………….

5b1 mark

Figure 1 shows the structure of two giant covalent structures: graphene and buckminsterfullerene.

edx-1-5e-paper-2-q5b-graphene-and-bucky

                                                   Graphene                                                            buckminsterfullerene

Figure 1

Buckminsterfullerene is also called C60.

State why.

5c1 mark

Graphene is very strong.

Use its structure to explain why.

5d1 mark

In the future, graphene could be used for touchscreens on electronic devices.

Other than its strength, give one property that would make it ideal for this job.

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11 mark

Different substances have characteristic melting and boiling points, depending on the strength of the bonds or forces holding them together.

Which explains why methane has a lower melting point than sodium chloride? 

  A Covalent bonds are weaker than ionic bonds
  B Intermolecular forces are weaker than ionic bonds
  C Covalent bonds are stronger than ionic bonds
  D Intermolecular forces are stronger than ionic bonds

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2a2 marks

This question is about alkenes and polymers.

Ethene (C2H4) can be represented by different types of formula.

 Complete the table by giving the missing information. 

Molecular formula  C2H4
Empirical formula  
General formula  

2b3 marks

Ethene is used to make poly(ethene).

 
i)
State the type of polymerisation used to form poly(ethene).

(1)

ii)
Complete the equation for the polymerisation of ethene.

(2)

alkene-addition-reaction

2c1 mark

The diagram shows the repeat unit of another polymer.

repeat-unit-of-a-polymer

Draw the displayed formula of the monomer used to make this polymer.

2d5 marks

Poly(ethene) is used to make plastic bags.

Corn starch from plants can also be used to make polymers for plastic bags.

The table gives some information about poly(ethene) and polymers made from corn starch.

 
  Poly(ethene) Polymers from corn starch
Cost per tonne £1500 £3700
Relative strength 100 50
Time to decompose estimated 450 years 3-6 months

Use the information in the table and your knowledge to discuss the advantages and disadvantages of using poly(ethene) to make plastic bags.

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31 mark

Sodium chloride is often known as 'table salt'. 

Which compound represents sodium chloride?

 
      Conducts electricity when solid Conducts electricity when molten State at room temperature and pressure Can be bent or shaped
  A Yes Yes Solid Yes
  B No No Solid No
  C No Yes Solid No
  D No No Solid Yes

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4a1 mark

A student used the equipment in Figure 1 to investigate whether electricity can pass through solids and through solutions.

testing-electrical-conductivity

Figure 1

Suggest why a lamp is included in the circuit.

4b5 marks

Copper wires are used to connect the circuit.

 
i)
Describe the structure and bonding in copper.
 (4)
ii)
Explain how copper is able to conduct electricity.
 (1)
4c2 marks

The student used graphite for the electrodes in this experiment.

Suggest two reasons why graphite is a suitable material to use as the electrodes.

 

4d4 marks

The student tested 2 solids and their solutions. Figure 2 shows the results of the investigation.

 
substance lamp
solid sugar did not light up
sugar solution did not light up
solid ammonium chloride did not light up
ammonium chloride solution lit up brightly

Figure 2

 

Explain the results of the investigation.

 

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51 mark

Covalent molecules can be displayed using a variety of diagrams and written formulae.

Which of the following shows the number of non-bonding electrons present in a molecule?

 
  A Dot and cross diagrams
  B Ball and stick diagrams
  C Molecular formula
  D All of the above

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1a4 marks

Carbon dioxide, diamond and graphite all have covalent structures.

Figure 1 shows their structure.

edx-1-5h-paper-2-q1a-carbon-substancesFigure 1

Carbon dioxide has a melting point of -57°C.

Diamond has a melting point of around 4500°C.

Explain this difference in terms of bonding.

1b2 marks

Predict if the melting point of graphite is closer to that of diamond or carbon dioxide.

Give a reason for your answer.

1c3 marks

Graphite is used as a lubricant.

Explain how its structure makes it good at this job.

1d2 marks

A single layer of graphite is called graphene.

Explain why graphene is a good conductor of electricity.

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2a1 mark

Table 1 shows information about two different substances, A and B.

Substance

Can it conduct electricity when solid?

Can it conduct electricity when molten?

A

No

Yes

B

No

No

Table 1

One of these substances is ionic and one is giant covalent.

Deduce, using the information in Table 1, which substance is which.

2b5 marks

Explain the properties of A and B in terms of their structure.

2c2 marks

Metals have a metallic structure.

Give two properties of a typical metal.

2d2 marks

All metals are malleable.

i)
Define malleable.

[1]

ii)
Use the structure of metals to explain why they are malleable.

[1]

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3a2 marks

Figure 1 shows two different fullerenes.

edx-1-5h-paper-2-q3a-fullerenes                 Buckminsterfullerene                                                                   Carbon nanotube

Figure 1

Describe what a fullerene is.

3b2 marks

Fullerenes have many uses. Explain how their structure makes them suitable for each job:

i)
Drug delivery

[1]

ii)
Increasing the efficiency of a catalyst

[1]

3c2 marks

Buckminsterfullerene has a low melting point.

Suggest why, in terms of its structure.

3d2 marks

Carbon nanotubes are used to make tennis racket frames.

Suggest why, using structure and bonding.

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4a1 mark

This question is about polymers.

Figure 1 shows the reaction used to make the polymer poly(ethene).

edx-1-5h-paper-2-q4a-polymer

Figure 1

Complete Figure 1 to show the structure of poly(ethene).

4b1 mark

Name this reaction.

4c2 marks

Poly(ethene) is a solid at room temperature.

Suggest why in terms of its structure and bonding.

4d2 marks

There are two types of poly(ethene). These are shown in Figure 2.

 edx-1-5h-paper-2-q4d-polyethene

                                      Type A                                                                                                Type B

Figure 2

Identify which type of poly(ethene) has the highest density.

Give a reason for your answer.

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5a2 marks

 Figure 1 shows two different models, X and Y, that represent an ionic structure.

edx-1-5h-paper-2-q5a-ionic-structure

                                                                                                                             Y

Figure 1

What do the different colour spheres represent in the models?

5b3 marks

Evaluate model X.

You should mention the advantages and limitations.

5c4 marks

Table 1 shows the melting points for two different ionic substances.

Ionic compound

Formula

Melting point in °C

Sodium chloride

NaCl

801

Magnesium oxide

MgO

2800

 Table 1

Suggest a reason for the difference in melting points.

5d4 marks

The melting point of sodium fluoride (NaF) is 992°C.

Predict if the melting point of rubidium fluoride (RbF) is higher or lower.

Give a reason for your answer.

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