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100 mL of a solution contains 2 g of acetic acid and 3 g of sodium acetate providing $K_a=1.8 \times 10^{-5}$, then choose the correct option.
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Verified Answer
The correct answer is:
This solution is acidic in nature
We have the formula for pH
$\mathrm{pH}=-\log K_a+\log \frac{[\text { Salt }]}{[\text { Base }]}$
$[$ Salt $]=\frac{3 \times 1000}{82 \times 100} \mathrm{~mol} \mathrm{~L}^{-1}$
and
$\begin{aligned} {[\text { Acid }] } & =\frac{2 \times 1000}{60 \times 100} \mathrm{~mol} \mathrm{~L}^{-1} \\ \mathrm{pH} & =-\log 1.8 \times 10^{-5}+\log \frac{\frac{3 \times 1000}{82 \times 100}}{\frac{2 \times 1000}{60 \times 100}} \\ \mathrm{pH} & =4.7851\end{aligned}$
$\mathrm{pH}=-\log K_a+\log \frac{[\text { Salt }]}{[\text { Base }]}$
$[$ Salt $]=\frac{3 \times 1000}{82 \times 100} \mathrm{~mol} \mathrm{~L}^{-1}$
and
$\begin{aligned} {[\text { Acid }] } & =\frac{2 \times 1000}{60 \times 100} \mathrm{~mol} \mathrm{~L}^{-1} \\ \mathrm{pH} & =-\log 1.8 \times 10^{-5}+\log \frac{\frac{3 \times 1000}{82 \times 100}}{\frac{2 \times 1000}{60 \times 100}} \\ \mathrm{pH} & =4.7851\end{aligned}$
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