Question

Question 26.
Equal volumes of hydrochloric acid and sodium hydroxide solutions of same concentration are mixed on the pH paper. What would be the colour obtained? (You may use colour guide given in figure of NCERT Book (Science Class X) on page 26).

(a) Red
(b) Yellow
(c) Yellowish green
(d) Blue

Answer 1

The reaction between hydrochloric acid and sodium hydroxide is a neutralisation reaction. The reaction involved is:

$\text{HCl}+\text{NaOH}\to \text{NaCl}+{\text{H}}_2\text{O}$

Since the resulting solution is obtained as a result of neutralisation reaction the colour of the neutral solution (with pH = 7) obtained is yellowish green.