A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of ([ CH 3 CH 2 COO -]/[ CH 3 CH 2 COOH ]) required to make buffer is .......... Given: K a ( CH 3 CH 2 COOH )=1.3 × 10-5

Question

A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH 4. The ratio of ([ CH 3 CH 2 COO -]/[ CH 3 CH 2 COOH ]) required to make buffer is .......... Given: K a ( CH 3 CH 2 COOH )=1.3 × 10-5 (A) 0.03 (B) 0.13 (C) 0.23 (D) 0.33

Tardigrade Admin · Accepted Answer

pH = pK a + log ([ text Salt ]/[ text Acid ]) 4=5- log 1.3+ log ([ CH 3 CH 2 COO -]/[ CH 3 CH 2 COOH ]) log ([ CH 3 CH 2 COO -]/[ CH 3 CH 2 COOH ])= log 1.3-1= log (1.3/10) ([ CH 3 CH 2 COO -]/[ CH 3 CH 2 COOH ])=0.13

Q. A student needs to prepare a buffer solution of propanoic acid and its sodium salt with $p H 4$ . The ratio of $\frac{[ C H _{3} C H _{2} CO O ^{-} ]}{[ C H _{3} C H _{2} COO H ]}$ required to make buffer is ..........
Given : $K_{a} (C H_{3} C H_{2} COO H) = 1.3 \times 1 0^{- 5}$

$0.03$

$0.13$

$0.23$

$0.33$

Q. A student needs to prepare a buffer solution of propanoic acid and its sodium salt with pH4. The ratio of [CH3​CH2​COOH][CH3​CH2​COO−]​ required to make buffer is .......... Given : Ka​(CH3​CH2​COOH)=1.3×10−5

0.03

0.13

0.23

0.33

pH=pKa​+log[ Acid ][ Salt ]​ 4=5−log1.3+log[CH3​CH2​COOH][CH3​CH2​COO−]​ log[CH3​CH2​COOH][CH3​CH2​COO−]​=log1.3−1=log101.3​ [CH3​CH2​COOH][CH3​CH2​COO−]​=0.13

Q. A student needs to prepare a buffer solution of propanoic acid and its sodium salt with $p H 4$ . The ratio of $\frac{[ C H _{3} C H _{2} CO O ^{-} ]}{[ C H _{3} C H _{2} COO H ]}$ required to make buffer is ..........
Given : $K_{a} (C H_{3} C H_{2} COO H) = 1.3 \times 1 0^{- 5}$

$0.03$

$0.13$

$0.23$

$0.33$