1. The atomic number of calcium is 20 and that of chlorine is 17. a) Write the electron arrangements ( electron configurations ) of calcium and chlorine,
showing the number of electrons in each shell: (2 marks)
Ca: Cl:

b) What type of bond is formed when calcium combines with chlorine? (1 mark)

c) Write the formula of the compound formed between calcium and chlorine. ( 1mark)

d) Compare the melting point of calcium chloride with that of water and explain why
the melting points are different. ( 2 marks)

e) Molten calcium chloride is electrolyzed using graphite electrodes. (2marks)
(i) What is formed at the cathode?

(ii) What is formed at the anode?

2. Zinc metal was reacted with 100 cm 3 of 0.2 mol/ dm 3 hydrochloric acid to produce zinc
chloride and hydrogen gas according to the equation below :
Zn(s) + 2HCl (aq) → ZnCl 2 (aq) + H 2
a) Calculate the number of mol of hydrochloric acid ( 2marks)

b) Calculate the number of mol of zinc chloride produced. (1 mark)

c) Calculate the mass in grams of zinc chloride produced. (3 marks)

d) Calculate the number of mol of hydrogen gas produced ( 1 mark)

e) Calculate the volume in dm 3 of hydrogen gas produced at r. t.p. ( 2 marks)

Data provided: Relative atomic masses (A r values) Zn = 65, Cl =35.5, I mole of any gas at r. t.p.
(room temperature and pressure) = 24 dm 3

3. A compound of magnesium (Mg) and bromine (Br) contains 13.0 % by mass of
magnesium and 87.0 % by mass of bromine.
Calculate the empirical formula of the compound. (3 marks)
Relative atomic masses (A r values): Mg =24, Br = 80

4. From the following list of elements in the Periodic Table: ( 10 marks)
Fe, N, Cl, Ca, Kr, Cu, Na, Si, Mg, Ar, F, P,
Write the symbols of the elements which:
a) Have high density

b) Have two electrons in the outer shell

c) Have five electrons in the outer shell

d) Have eight electrons in their outer shells

e) Have seven electrons in their outer shells.