Question

Calculate the concentration of OH in a solution that contains 3910-4 M H30 at 25°C. Identify the solution as acidic, basic or neutral OA) 2.6 10-11 M, acidic OB)26 10-11 M. basic O c) 3.9 x 10-4 M, neutral OD) 2.7 * 10-2 M

Answer 1

Answer : The correct option is, (A)
`2.6* 10^(-11)M`, acidic

Step-by-step explanation:

pH : It is defined as the negative logarithm of hydrogen ion or hydronium ion concentration.

When the value of pH is less then 7 then the solution will be acidic.

When the value of pH is more then 7 then the solution will be basic.

When the value of pH is equal to 7 then the solution will be neutral.

First we have to calculate the pH.

`pH=-\log [H^+]`

`pH=-\log (3.9* 10^(-4))`

`pH=3.41`

Now we have to calculate the pOH.

`pH+pOH=14\\\\pOH=14-pH\\\\pOH=14-3.41=10.59`

Now we have to calculate the
`OH^-` concentration.

`pOH=-\log [OH^-]`

`10.59=-\log [OH^-]`

`[OH^-]=2.6* 10^(-11)M`

Therefore, the
`OH^-` concentration is,
`2.6* 10^(-11)M`