Chemistry
(a) What is a decomposition reaction ?
(b) Decomposition reactions can occur by (i) heat (ii) electricity and (iii) sunlight.
Give two balanced reactions for each.
Related Questions
What do you understand by precipitation reaction? Explain with an example.
(a) What are double displacement reactions?
(b) Give an example of a double displacement reaction, where gas is evolved.
State the type of reactions each of the following represent and balance the ones that are not balanced.
(a) Cl2 + 2KBr ⟶ 2KCl + Br2
(b) NaOH + HCl ⟶ NaCl + H2O
(c) 2HgO ⟶ 2Hg + O2 ↑
(d) Fe + CuSO4 ⟶ FeSO4 + Cu
(e) PbO2 + SO2 ⟶ PbSO4
(f) 2KClO3 ⟶ 2KCl + 3O2 ↑
(g) 2H2O2 ⟶ 2H2O + O2 ↑
(h) KNO3 + H2SO4 ⟶ HNO3 + KHSO4
(i) CuO + H2 ⟶ Cu + H2O
(j) CaCO3 ⟶ CaO + CO2 ↑
(k) NH4Cl ⟶ NH3 + HCl
(l) PbO + 2HNO3 ⟶ Pb(NO3)2 + 2H2O
(m) AgNO3 + NaCl ⟶ AgCl ↓ + NaNO3
Which of the of following is not a chemical change.
- Rusting of iron
- Iron is magnetised
- Potassium is dissolved in water
- Magnesium wire is burnt