Question

If $1$ stands for true and $0$ stands for false, then choose the correct code for the following statement:
Concentration of $N{a}_{2}C{O}_3$ solution can be determined by titration with acid solution using methyl red as the indicator.

Answer 1

Concentration of $N{a}_{2}C{O}_3$ solution can be determined by titration with acid solution using methyl red as the indicator.
Phenolphthalein indicator operates in the pH range $8.0-9.8$. At this pH, only one hydrogen ion can be added to carbonate ion to form bicarbonate ion. Hence, only $50\%$ of sodium carbonate solution is indicated if it is neutralized by HCl using phenolphthalein as the indicator.
Methyl red indicator operates in the pH range $4.2-6.3$.

At this pH, two hydrogen ions can be added to carbonate ion to form carbonic acid. Hence, $100\%$ of sodium carbonate solution is indicated if it is neutralized by HCl using methyl red as the indicator.