CBSE 2023 · Region 2 · Set 1 · Q37

The teacher while conducting practicals in the laboratory divided the students into three groups and gave them various solutions to find out their pH and classify them into acidic, basic and neutral solutions. Group A - Lemon juice, vinegar, colourless aerated drink Group B - Tomato juice, coffee, ginger juice Group C - Sodium hydroxide, sodium chloride, lime water

(a)

For the solutions provided, which group is/are likely to have pH value (i) less than $\displaystyle 7$, and (ii) greater than $\displaystyle 7$ ?

(b)

List two ways of determining pH of a solution

(c)OR(c)

Explain, why the sour substances such as lemon juice are effective in cleaning the tarnished copper vessels.