Question

What will be degree of ionisation when complete weak acid solution is mixed with complete strong acid solution ?

• A. $5\times {10}^{-3}$
• B. $2\times {10}^{-3}$
• C. $2\times {10}^{-4}$
• D. $5\times {10}^{-4}$

Answer 1

The correct option is C $2\times {10}^{-4}$

$pH=P{K}_a+\log \frac{\left[salt\right]}{\left[acid\right]}$
$4.7=P{K}_a+\log \frac{50\times 0.1}{100\times 0.1}$
$P{K}_a=5K_a={10}^{-5}$
$HA+BOH\rightleftharpoons BA+H_{2}O$
150 0.1 50 0.1
$\frac{100\times 0.1}{weakacid}$
$Bottle\left(A\right)=WeakacidBottle$
$\left(B\right)=Strongbase$
$Bottle\left(C\right)=Strongacid$