Question

The resulting solution obtained at the end of electrolysis of concentrated aqueous solution of $NaCl:$

• A. Turns blue litmus into red
• B. Turns red litmus into blue
• C. Remains colourless with phenolphthalein
• D. Colour of red or blue litmus does not change

Answer 1

The correct option is B Turns red litmus into blue

During the electrolysis of aqueous sodium chloride solution, the products are $NaOH,C{l}_2$ and $H_2$.
$NaCl\left(aq\right)+H_{2}O\left(l\right)\to N{a}^{+}\left(aq\right)+O{H}^{-}\left(aq\right)+\frac{1}{2}{H}_2\left(g\right)+\frac{1}{2}C{l}_2\left(g\right)$
Due to formation of base, it turns res litmus into blue.