Chemical Reactions and Equations
- Why is the amount of gas collected in one of the test tubes in Activity 1.7 double Water contains two parts of hydrogen and one part oxygen. Therefore, during the electrolysis of water the amount of hydrogen gas collected i... 1
- A solution of a substance ‘X’ is used for white washing. (i) The substance 'X' is calcium oxide. Its chemical formula is CaO. (ii) Calcium oxide reacts vigorously with water to form calcium hydroxi... 1
- Write the reaction of the substance ‘X’ named in (i) above with water. Calcium oxide reacts vigorously with water to form calcium hydroxide (slaked lime). CaO (s) + H₂O (l) → Ca(OH)₂ (aq) Calcium Oxide (Quick Li... 2
- (i) Name the substance ‘X’ and write its formula. The substance 'X' is calcium oxide. Its chemical formula is CaO. 1
- Sodium hydroxide solution (in water) reacts with hydrochloric acid solution (in water) (ii) NaOH (aq) + HCl (aq) → NaCL (aq) + H₂O (l) 2
- Solutions of barium chloride and sodium sulphate in water react to give insoluble barium (i) BaCl₂ (aq) + Na₂SO₄ (aq) → BaSO₄ (s) + 2NaCl (aq) 2
- Write the balanced equation for the following chemical reactions. (i) H₂ (g) + Cl₂ (g) → 2HCl (g) (ii) 3BaCl₂ (s) + Al₂(SO₄)₃ (s) → 3BaSO₄ (s) + 2AlCl₃ (s) (iii) 2Na(s) + 2H₂O (l) → 2NaOH (aq) + H₂ (g) 1
- Why should a magnesium ribbon be cleaned before it is burnt in air? Magnesium is a very reactive metal. When stored, it reacts with oxygen to form a layer of magnesium oxide on its surface. This layer of magn... 1