Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed and the pH of the resulting solution is checked with a pH paper. What would be the colour obtained?
Red
Yellow
Yellowish green
Blue
Steps: Equal volumes of equal concentration HCl and NaOH neutralise to give a neutral solution (pH ≈ 7). On the pH colour chart, pH 7 corresponds to greenish (yellowish-green). Hence yellowish green.