Question
This question is about Group IV elements and their compounds.
(a) The changes of state of lead are shown.
Name the changes of state represented by A and B.[2]
A
B
(b) Use the kinetic particle model to describe the differences between liquid lead and lead gas in terms of:[4]
-
- the separation of the particles
- the motion of the particles.
(c) Lead is extracted from lead(II) oxide by heating with carbon.
PbO + C → Pb + CO
Describe how this equation shows that lead(II) oxide is reduced.[1]
(d) Lead is a pollutant of the air.
(i) State one source of lead in the air.[1]
(ii) State one adverse effect of lead on health.[1]
(e) Diamond is a form of carbon.
The structure of diamond is shown.
(i) Choose the word which best describes the structure of diamond.
Draw a circle around your chosen answer.[1]
giant ionic metallic simple
(ii) Name the type of bonding in diamond.[1]
(iii) Give one use of diamond.[1]
(iv) Deduce the electronic structure of carbon.
Use the Periodic Table to help you.[1] [Total: 13]
Answer/Explanation
Ans:
a) A: freezing (1)
B: boiling (1)
b) separation:
liquid: close together / some touching (1)
gas: far apart (1)
motion:
liquid: sliding over each other / restricted movement (1)
gas: moving freely (1)
(c) lead oxide has lost oxygen
(d)(i) (leaded) petrol / paints
(d)(ii) poisonous / toxic / harms nerves / harms brain
(e)(i) giant
(e)(ii) covalent
(e)(iii) cutting tools / for cutting / drill tips / jewelry
(e)(iv) 2,4
Question
(a) The structures of four substances C, D, E and F, are shown.
(i) Which one of these substances, C, D, E or F, is a gas at room temperature?
(ii) What type of bonding is present in substance E?
(iii) Which one of these substances, C, D, E or F, is soluble in water?
(iv) Which one of these substances, C, D, E or F, conducts electricity when solid?
(b) The halogens have molecules containing two atoms.
What is the name for molecules containing only two atoms?
(c) The reaction of iodine with hydrogen is shown.
\(I_2 + H_2 \leftrightarrow 2HI\)
What is the meaning of the symbol \(\leftrightarrow\)?
(d) Iodine is formed when chlorine reacts with aqueous potassium iodide.
(i) Complete the chemical equation for this reaction.
\(………. + 2KI → I_2 + …….KCl\)
(ii) When aqueous iodine is mixed with aqueous potassium chloride, there is no reaction.
Suggest, in terms of chemical reactivity, why there is no reaction.
Answer/Explanation
Answer:
(a) (i) F
(ii) ionic
(iii) E
(iv) D
(b) diatomic
(c) reversible reaction / the reaction can go forwards or backwards
(d) (i) \(Cl_2\) (on left) (1)
2 (KCl) (on right) (1)
(ii) chlorine is more reactive than iodine / iodine is less reactive than chlorine
Question
The diagram shows part of the structures of sodium bromide and sulfur.
(a) Describe both sodium bromide and sulfur in terms of:
- bonding………………………………………………….
- electrical conductivity……………………………..
- solubility in water…………………………………….[5]
(b) Sulfur is an element. What is meant by the term element? [1]
(c) Sodium can be extracted from sodium bromide by electrolysis. Sodium is a metal in Group I of the Periodic Table.
(i) Describe one chemical property of sodium.
……………………………………………………………………………………………………………………… [1]
(ii) Which two of these statements about the physical properties of sodium are correct?
Tick two boxes.
[2] [Total: 9]
▶️Answer/Explanation
Ans:
(a) for bonding (maximum three marks)
one mark each for any three of:
• sodium bromide – bonding is ionic
• sodium bromide – strong bonding (between ions)
• sulfur – weak forces between molecules
• sulfur – covalent bonds within molecules
(a) for electrical conductivity (maximum two marks)
one mark each for any three of:
• sodium bromide – conducts when molten / conducts in aqueous solution
• sodium bromide – does not conduct when solid
• sulfur – does not conduct
For solubility in water (maximum two marks)
• sodium bromide – soluble in water
• sulfur– insoluble in water
(b) substance containing only one type of atom / substance which cannot be broken down to simpler substances by
chemical means
(c)(i) reacts with water / reacts with chlorine
(c)(ii) third box ticked (sodium conducts electricity)
fourth box ticked (sodium is malleable)