Decomposition reactions are brought about by ________

(a)

heat

(b)

light

(c)

electricity

(d)

all the above

When Zinc metal is placed in hydrochloric acid, the gas evolved is _________________

(a)

CO

(b)

CO₂

(c)

H₂

(d)

H₂O

Pick out a chemical reaction which is not feasible

(a)

2NaCI ⟶ 2Na + Cl₂

(b)

2NaCI + F ⟶ 2NaF + Cl₂

(c)

2NaF + Cl₂ ⟶ 2NaCI + F

(d)

NaOH + HCI ⟶ NaCl + H₂O

Pick out the metal that displaces hydrogen from hydrochloric acid.

(a)

Zinc

(b)

Silver

(c)

Copper

(d)

Gold

When a double displacement reaction takes place, one of the products must be

(a)

Precipitate

(b)

Water

(c)

either (a) or (b)

(d)

neither (a) nor (b)