Page 50 - ACE YR IGCSE A TOP APPROACH TO CHEM

Chemical property: [1] (iii) Nitrogen and neon
• Reducing agent / Reduces metal oxides / Physical property: [1]
named metal oxide • Nitrogen is diatomic at room temperature,
• Reacts with / burns in air / oxygen but neon is monatomic.
• Forms an acidic oxide (CO ) Chemical property: [1]
2
• Valency / oxidation state of 2 or 4
• Nitrogen reacts with a metal and a non-
(iii) Titanium metal, but neon does not.
Physical property: [1] • Nitrogen has a valency of 3, but neon has
• A conductor of heat / electricity a zero valency.
• High melting point / High boiling point • Nitrogen is colourless, but neon is
• Forms coloured compounds / coloured coloured.
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ions
• Hard / Strong 9 Metals
• High density
• Malleable Part 1: Multiple-choice Questions
• Ductile
• Sonorous 1 B
• Shiny Vanadium is a metal. There are free moving electrons.
Chemical property: [1] 2 B
• Variable or different valency / oxidation Bronze is a mixture of copper and tin.
state / oxidation number 3 C
• Catalytic activity Iron is a metal. There are free moving electrons.
• Forms coloured compounds / coloured 4 A
ions Making an alloy is to strengthen the properties of an
• Forms complex ions / complexes element so that it is more useful.
• Reacts with acids
• An reducing agent 5 D
• Reacts with non-metals Only very reactive metal reacts with cold water.
Potassium is very reactive.
(b) Any one from: 6 C
(i) Oxygen and chlorine The bigger the distance between two metals in the
Physical property: [1] reactivity series, the greater the voltage.
• Chlorine is a coloured gas, but oxygen is
colourless. 7 A
• Chlorine is poisonous, but oxygen is not. A more reactive metal can displace a less reactive metal
from its compound. Sodium is more reactive than
Chemical property: [1] magnesium.
• Chlorine bleaches litmus paper, but 8 C
oxygen does not. Any metal above carbon in the reactivity series cannot
• Chlorine has a valency of 1, but oxygen be reduced by carbon.
has a valency of 2.
9 D
(ii) Lithium and iron Stainless steel is made of iron, nickel and chromium.
Physical property: [1] Mild steel is made of iron and carbon.
• Iron is hard, but lithium is soft. 10 C
• Iron has a higher density than lithium. These are displacement reactions.
• Iron has a higher melting point than Lead cannot react with all metal compounds. So, it is the
lithium. least reactive.
Chemical property: [1] Zinc reacted with all metal compounds. So, it is the most
reactive.
• Iron forms a coloured compound, but Iron reacted with two metal compounds, and tin reacted
lithium forms a white compound. with one metal compound.
• Iron has catalytic activity, but lithium So, iron is more reactive than tin.
does not. Lead < tin < iron < zinc
• Iron has different oxidation states, but
lithium has only 1. 11 A
• Iron is less reactive than lithium. Aluminium is very reactive. It reacts with oxygen to
form aluminium oxide when exposed to air. Aluminium
oxide is a non-porous layer. The acid has to react with
aluminium oxide before reacting with aluminium.

Cambridge IGCSE TM
162 Ace Your Chemistry

Answers.indd 162 3/4/22 3:54 PM