Question

Statement: In the titration of Na${}_2$CO${}_3$ with HCl using methyl orange indicator, the volume of the acid required at the equivalence point is twice that of the acid required using phenolphthalein as an indicator.

State whether the given statement is true or false.

• A. True
• B. False

Answer 1

The correct option is A True

Since phenolphthalein is a weak organic acid, and it changes its colour in weakly basic medium $\left(NaHC{O}_3\right)$, so as soon as the $N{a}_{2}C{O}_3$ is converted to $NaHC{O}_3$ phenolphthalein shows the colour change indicating the completion of the reaction.

In the presence of methyl orange, all the basic substances left in the mixture will be neutralized by acid and methyl orange will show the colour change when the medium is weakly acidic.

$(H_{2}O+C{O}_2$ i.e. $H_{2}C{O}_3).$

Hence, the correct option is $\text{true}$