This question is about metals and metal compounds
Iron pyrites is an ionic compound. Figure 1 shows a structure for iron pyrites.
Figure 1
Determine the formula of iron pyrites. Use Figure 1.
[1 mark]
ANSWER
FeS2
An atom of iron is represented as F e 26 56
Give the number of protons, neutrons and electrons in this atom of iron.
[3 marks]
Number of protons: ______________
Number of neutrons: ______________
Number of electron: ______________
ANSWER
Number of protons: 26
Number of neutrons: 30
Number of electron: 26
Iron is a transition metal. Sodium is a Group 1 metal.
Give two differences between the properties of iron and sodium.
[2 marks]
ANSWER
Student may select any two (as required):
iron has a higher melting / boiling point as compared to Group 1 metal Sodium metal
iron is denser than Group 1 metal Sodium metal
iron is harder than Group 1 metal Sodium metal
iron is stronger than Group 1 metal Sodium metal
iron is less reactive than Group 1 metal Sodium metal
iron has ions with different charges while Group 1 metal Sodium metal has only single charge i.e. +1
iron forms coloured compounds while Group 1 metal Sodium metal form white solids
iron can be a catalyst while Group 1 metal Sodium metal cannot
Nickel is extracted from nickel oxide by reduction with carbon.
Explain why carbon can be used to extract nickel from nickel oxide.
[2 marks]
ANSWER
Carbon is more reactive than nickel so carbon will displace or replace nickel from nickel oxide or in other words carbon will remove oxygen from nickel oxide.
An equation for the reaction is: NiO + C Ni + CO
Calculate the percentage atom economy for the reaction to produce nickel.
Relative atomic masses (Ar): C = 12, Ni = 59; Relative formula mass (Mr): NiO = 75. Give your answer to 3 significant figures.
[3 marks]
ANSWER
