Chemistry
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
Related Questions
(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.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
Heating of zinc nitrate is a …………… reaction.
- Displacement
- Combination
- Decomposition
- Redox
Burning of a metal is an example of :
- Decomposition reaction
- Combination reaction between an element and a compound
- Direct combination reaction between two elements
- Displacement reaction