11. The following statements relate to the extraction of metals:

I. Unreactive metals are often found as uncombined elements
II. Iron is more difficult to extract than copper
III. Sodium is extracted from its ore by heating with carbon

Which of these statements are true?

  • A.   I and II only
  • B.   I and III only
  • C.   II and III only
  • D.   I, II and III

Q12-13:
One of the reactions in the extraction of zinc is:

ZnO  + C → Zn + CO

  
12. Carbon is used to extract zinc from zinc oxide because ..
  • A.   carbon is less reactive than zinc
  • B.   carbon is more reactive than zinc
  • C.   carbon is a non-metal
  • D.   carbon is cheap
13. Which statement is correct about this reaction?
  • A.   carbon is reduced to carbon monoxide
  • B.   carbon monoxide is reduced to carbon
  • C.   zinc is oxidized to zinc oxide
  • D.   zinc oxide is reduced to zinc
14. Iron can be extracted in a blast furnace. The metal oxides are reduced by carbon monoxide, CO.

 

blast furnace
J Navas | CC 3.0

The chemical equation for the reduction of iron(III)oxide, Fe2O3 is..

  • A. Fe2O3 + CO → Fe2 + CO2
  • B. Fe2O3 + 3CO → Fe2 + 3CO2
  • C. Fe2O3 + CO → Fe + CO2
  • D. Fe2O3 + 3CO → 2Fe + 3CO2
15. Sodium metal and sodium chloride both have giant lattice structures.

State the types of particle(s) present in each substance.

  
  sodium Sodium chloride
A cations and delocalized electrons Cations and anions
B cations and delocalized electrons molecules
C atoms Cations and anions
D atoms molecules
16. Aluminium is extracted from molten aluminium oxide by electrolysis.

Which substances are formed at each electrode?

  anode cathode
A aluminium oxygen
B aluminium hydrogen
C oxygen aluminium
D hydrogen aluminium
17. Magnesium is extracted from magnesium chloride found in salt brines. The magnesium chloride is first separated from the brine and then electrolyzed.

What is the formula of magnesium chloride and should molten or aqueous magnesium chloride be used for the electrolysis?

  
  Formula State
A MgCl molten
B MgCl aqueous
C MgCl2 molten
D MgCl2 aqueous
18. When copper(I)oxide is heated with magnesium a redox reaction occurs. The equation for the reaction is:

2Cu2O + Mg → 2Cu + MgO

  

Identify the reducing agent in this reaction.

  • A.   Cu2O
  • B.   Mg
  • C.   Cu
  • D.   MgO
19. Bronze is an alloy of tin and copper.

The diagrams show the arrangement of atoms in pure copper and in bronze.

particles in copper and bronze

Which of the following statements about copper and bronze are true?

I. Bronze is less malleable than pure copper
II. Tin atoms distort the copper lattice preventing the layers of copper atoms from sliding over each other
III. Tin and copper atoms are chemically combined in the lattice
 
  • A.   I and II only
  • B.   I and III only
  • C.   II and III only
  • D.   I, II and III
20. Mild steel is an alloy of iron and carbon. Which statement is true?
  • A.   The carbon makes the alloy softer than iron
  • B.   The carbon makes the alloy harder than iron
  • C.   The carbon stops the iron from rusting
  • D.   The carbon makes the alloy a better conductor than iron