Question

4ml of 0.5N Hcl is mixed with 1 ml of 2N KOH the PH of the resulting solution is

Answer 1

Given:

4mL of 0.5N $HCl$ is mixed with 1mL of 2N $KOH$

To find:

pH of resulting solution

Explanation:

For $HCl$  $\rightarrow N_{1}= 0.5N$

                   $V_{1}= 4mL$

            $\Rightarrow [H^{+}] = 4 \times 0.5 = 2$

Similarly for KOH $\rightarrow N_{2}= 2N$

                                 $V_{2}= 1mL$

            $\Rightarrow [OH^{-}] = 2 \times 1= 2$

As it can be seen  $[OH^{-} ] = [H^{+}]$  ,  neutralization reaction occurs since the concentration of $H^+$ions is equal to that of $OH^-$ions.

Therefore , by definition , pH for a neutral solution is 7 , pH= 7.