Chemistry
(a) A solution has a pH of 7. Explain how you would: (i) increase it's pH (ii) decrease it's pH.
(b) If a solution changes the colour of litmus from red to blue, what you can say about it's pH.
(c) What you can say about the pH of a solution, that liberates carbon dioxide from sodium carbonate?
Acids Bases Salts
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Answer
(a) A solution with pH of 7 is neutral. (i) Increasing it's pH means increasing its basic nature. Hence, we will add alkali to increase it's pH. (ii) Similarly, to decrease it's pH, we will add an acid to the solution.
(b) When a solution changes the colour of litmus from red to blue, it shows it is basic in nature and the pH value will be more than 7.
(c) Acids liberate carbon dioxide on reaction with metallic carbonates and bicarbonates. Hence, the pH of this solution will be less than 7.
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