The number of `H^(+)` ions present in 250 ml of lemon juice of pH=3 is

Options

A. `1.506 xx 10^(22)`
B. `1.506 xx 10^(23)`
C. `1.506 xx 10^(20)`
D. `3.012 xx 10^(21)`

Answer

C

Explanation

`pH =3` means `[H^(+)]=10^(-3)M`
`i.e. 1000mL `of joice contains `H^(+)=10^(-3)` mol
`=10^(-3) xx 6.02 xx 10^(23) H^(+)` ions
`:. 25 mL` of the juice contains `H^(+)` ions
`=(10^(-5) xx 6.02 xx 10^(23))/(1000)xx 250 =1.506 xx 10^(-20)`