Question

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? (You may use colour guide given in your text book)

• A. Red
• B. Yellow
• C. Yellowish green
• D. Blue

Answer 1

Answer: (C)

Yellowish green

$Acid+Base\to Salt+water$

When equal volumes of strong acid and base mix, they neutralize to give a salt solution with a pH of 7. A pH paper strip dipped in this salt solution will turn greenish-yellow.

$HCl+NaOH\to NaCl+H_{2}O$