17
Read the following passage and answer the questions that follow:
Various substances can be classified as acids, bases and salts. Based on their strength, acids and bases are further classified as strong and weak. We can find this by using universal indicators, which shows different colours at different concentrations of hydrogen ions in a solution. A pH scale has been developed, which indicates acidic or basic nature of a solution, from 0 (very acidic) to 14 (very alkaline).
(i) Define universal indicator.
Various substances can be classified as acids, bases and salts. Based on their strength, acids and bases are further classified as strong and weak. We can find this by using universal indicators, which shows different colours at different concentrations of hydrogen ions in a solution. A pH scale has been developed, which indicates acidic or basic nature of a solution, from 0 (very acidic) to 14 (very alkaline).
(i) Define universal indicator.
Show SolutionHide Solution↓
(i) An indicator which shows different colours at different hydrogen ion concentration/ different pH values in a solution. (1 Mark)
(ii) 'A' (1 Mark)
(iii) (a) The reaction of an acid and a base to form salt and water. (1 Mark)
$\ce{NaOH + HCl -> NaCl + H2O}$ (1 Mark)
(or any other) (4 Marks)
(iii) (b) (I) Strongly alkaline – D (1 Mark)
(II) Strongly acidic – B (1 Mark) (4 Marks)
(ii) 'A' (1 Mark)
(iii) (a) The reaction of an acid and a base to form salt and water. (1 Mark)
$\ce{NaOH + HCl -> NaCl + H2O}$ (1 Mark)
(or any other) (4 Marks)
(iii) (b) (I) Strongly alkaline – D (1 Mark)
(II) Strongly acidic – B (1 Mark) (4 Marks)