The dissociation constant of weak acid is `1 times 10^-3`. In order to prepare a buffer solution a pH=4, the [Acid]/[Salt] ratio should be……

Options

A. `4:3`
B. `3:4`
C. `10:1`
D. `1:10`

Explanation

`K_a=1 times 10^-3,pH=4`
` ([sal t])/([acid])=?`
`pH=pK_a+log([sal t])/([acid])`
`4=-log_10(1 times 10^-3)+log([sal t])/([Acid])`
`4=3+log ""([Sal t])/([Acid])`
`1=log_10""([sal t])/([acid])=implies([sal t])/([acid])=10^1`
i.e., `([acid])/([sal t])=1/10 implies1:10`