Equal volumes of 0.5N acetic and 0.5N sodium acetate are mixed. What is the pH of resultant solution? ($p{K}_a$ of acetic acid=4.75)

Given concentration of acetic acid, 

$\left[C{H}_{3}COOH\right]=0.5N$

Concentration of sodium acetate, 

$\left[C{H}_{3}COONa\right]=0.5N$

$p{K}_a$ of  $C{H}_{3}COOH=4.75$

Using Henderson Hasselbalch equation

$pH=p{K}_a+\log \frac{\left[{\mathrm{CH}}_3\mathrm{COONa}\right]}{\left[{\mathrm{CH}}_3\mathrm{COOH}\right]}$

$\Rightarrow$ $p^H=4.75+\log \frac{0.5}{0.5}$

So,$p^H=$ $4.75+\log 1=4.75+0$

$=4.75$