Question

How many of the following combination act as buffer

$\left(\right.1\left.\right)$ HCl + NaOH

$\left(\right.2\left.\right)$ $CH_{3}COONa+CH_{3}COOH$

$\left(\right.3\left.\right)$ $H_{2}SO_{4}+Na_{2}SO_{4}$

$\left(\right.4\left.\right)$ $H_{2}CO_{3}+NaOH$

$\left(\right.5\left.\right)$ $Na_{2}B_{4}O_{7}+H_{3}BO_{3}$

$\left(\right.6\left.\right)$ $NH_{4}OH+NH_{4}Cl$

• A. 3
• B. 4
• C. 2
• D. 6

Answer 1

Answer: (B)

Buffer are

(1) $CH_{3}COONa+CH_{3}COOH$

(2) $H_{2}CO_{3}+NaOH$

(3) $Na_{2}B_{4}O_{7}+H_{3}BO_{3}$

(4) $NH_{4}OH+NH_{4}Cl$