Question

(a) What are metals? Name five metals.
(b) Name a metal which is so soft that it can be cut with a knife.
(c) Name the metal which is the best conductor of heat and electricity.
(d) What happens when a metal reacts with dilute hydrochloric acid? Explain with the help of an example.
(e) Write the equations for the reaction of:
(i) Magnesium with dilute hydrochloric acid
(ii) Aluminium with dilute hydrochloric acid
(iii) Zinc with dilute hydrochloric acid
(iv) Iron with dilute hydrochloric acid
Name the products formed in each case. Also indicate the physical states of all the substances involved.

Answer 1

(a) Metals are generally solid materials that conduct heat and electricity. They are malleable and ductile and also lustrous, hard, strong, heavy and sonorous. Iron, aluminium, copper, gold and silver are five metals.

(b) Sodium is a metal that is so soft that it can be cut with a knife.

(c) Silver is the metal which is the best conductor of heat and electricity.

(d) When a metal reacts with dilute hydrochloric acid, it forms a metal chloride salt and hydrogen gas.
For example, sodium reacts with dilute hydrochloric acid to form sodium chloride salt and hydrogen gas.
2Na(s) + 2HCl(aq) $\to$2NaCl(aq) + H₂(g)

(e) (i) Magnesium reacts with dilute hydrochloric acid to form magnesium chloride and hydrogen gas.
Mg(s) + 2HCl(aq) $\to$MgCl₂(aq) + H₂(g)

(ii) Aluminium reacts with dilute hydrochloric acid to form aluminium chloride and hydrogen gas.
2Al(s) + 6HCl(aq) $\to$ 2AlCl₃(aq) + 3H₂(g)

(iii) Zinc reacts with dilute hydrochloric acid to form zinc chloride and hydrogen gas.
Zn(s) + 2HCl(aq) $\to$ ZnCl₂(aq) + H₂(g)

(iv) Iron reacts with dilute hydrochloric acid to form iron (II) chloride and hydrogen gas.
Fe(s) + 2HCl(aq) $\to$ FeCl₂(aq) + H₂(g)