Fixed volume of 0.1 M benzoic acid solution is added into 0.2 M sodium benzoate solution and formed a 300 ml , resultant acidic buffer solution. If pH of this buffer solution is 4.5 then find added volume of benzoic acid - (Given:pKa textbenzoic textacid = 4.2)

Question

Fixed volume of 0.1 M benzoic acid solution is added into 0.2 M sodium benzoate solution and formed a 300 ml , resultant acidic buffer solution. If pH of this buffer solution is 4.5 then find added volume of benzoic acid - (Given:pKa textbenzoic textacid = 4.2) (A) 100 ml (B) 150 ml (C) 200 ml (D) None of these

Tardigrade Admin · Accepted Answer

pH=pKa+log (s a l t/a c i d) 4.5=4.2+log (s a l t/a c i d) 0.3=log (s a l t/a c i d) (s a l t/a c i d)=2 (0.3 × (300 - v)/0.1 × v)=2 v=150 ml

Q. Fixed volume of $0.1 M$ benzoic acid solution is added into $0.2 M$ sodium benzoate solution and formed a $300 m l$ , resultant acidic buffer solution. If $p H$ of this buffer solution is $4.5$ then find added volume of benzoic acid -

$(G i v e n : p K_{a} benzoic acid = 4.2)$

$100 m l$

$150 m l$

$200 m l$

None of these

$p H = p K_{a} + l o g \frac{s a lt}{a c i d}$

$4.5 = 4.2 + l o g \frac{s a lt}{a c i d}$

$0.3 = l o g \frac{s a lt}{a c i d}$

$\frac{s a lt}{a c i d} = 2$

$\frac{0.3 \times ( 300 - v )}{0.1 \times v} = 2$

$v = 150 m l$

Q. Fixed volume of 0.1M benzoic acid solution is added into 0.2M sodium benzoate solution and formed a 300ml , resultant acidic buffer solution. If pH of this buffer solution is 4.5 then find added volume of benzoic acid - (Given:pKa​benzoicacid=4.2)

100ml

150ml

200ml