Question

(a) Chlorine reacts with hydrogen to make hydrogen chloride.
       (i) Construct the word equation for this reaction.
       (ii) Hydrogen chloride gas is a covalent compound.
              Explain why hydrogen chloride gas is a covalent compound and not an ionic compound.
        (iii) Fig. 5.1 shows the electronic structure in atoms of hydrogen and chlorine.

Draw a dot-and-cross diagram to show the arrangement of outer-shell electrons in a molecule of hydrogen chloride gas.

(iv) Hydrogen chloride dissolves in water to make dilute hydrochloric acid.
       The pH of the hydrochloric acid is found using a pH probe.
       Describe one other way of finding the pH of dilute hydrochloric acid.

(v) Suggest the pH of the dilute hydrochloric acid.

(b) Table 5.1 shows information about three Group VII elements.

(i) Complete Table 5.1. 
(ii) State the name given to Group VII of the Periodic Table.
(iii) Explain why chlorine, bromine and iodine are all in Group VII of the Periodic Table.
Use ideas about electrons in your answer.