Practice determining reaction classification

Question

For each of the reactions below, classify as a combination, decomposition, single replacement, or double replacement.

Ca(s) + Cl2(g) ⟶ CaCl2(s)

2Cu(s) + O2(g) ⟶ 2CuO(s)

Ca(NO3)2(aq) + H2SO4(aq) ⟶ 2HNO3(aq) + CaSO4(s)


NH3(aq) + HCl(aq) ⟶ NH4Cl(aq)

Answer 1

1. Combination reaction: Ca(s) + Cl2(g) ⟶ CaCl2(s)
2. Combination reaction: 2Cu(s) + O2(g) ⟶ 2CuO(s)
3. Double replacement reaction: Ca(NO3)2(aq) + H2SO4(aq) ⟶ 2HNO3(aq) + CaSO4(s)
4. Combination reaction: NH3(aq) + HCl(aq) ⟶ NH4Cl(aq)