(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 reactions 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.
(a) Metals are the elements that conduct heat and electricity, and are malleable and ductile.
Example: Iron, aluminium, copper, gold and silver.
(b) Sodium
(c) Silver
(d) When a metal reacts with dilute hydrochloric acid, it forms metal chloride and hydrogen gas.
Example: Magnesium reacts rapidly with dilute hydrochloric acid to form magnesium chloride and hydrogen.
Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
(e)(i) Mg(s) + 2HCl(aq) → MgCl2(aq) + H2(g)
The products formed are magnesium chloride and hydrogen.
(ii) 2Al(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2(g)
The products formed are aluminium chloride and hydrogen.
(iii) Zn(s) + 2HCl(aq) → ZnCl2(aq) + H2(g)
The products formed are zinc chloride and hydrogen.
(iv) Fe(s) + 2HCl(aq) → FeCl2(aq) + H2(g)
The products formed are iron chloride and hydrogen.