Question

What is the concentration of hydrogen ions [H+] in a solution of pH = 4.0?

1 × 104M
4 × 10–4M
2 × 10–2M
1 × 10–4M

Answer 1

all we need to do is used the following formula:

[H+] = 10^-pH

so

[H+]= 10^-4.0= 1 x 10^-4 M
the answer is the last choice

Answer 2

Answer:
`1* 10^(-4)M`

Step-by-step explanation:

pH or pOH is the measure of acidity or alkalinity of a solution.

pH is calculated by taking negative logarithm of hydrogen ion concentration and pOH is calculated by taking negative logarithm of hydroxide ion concentration.

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

`pOH=-log[OH^-]`

`pH+pOH=14`

Given: pH= 4.0

Putting in the values in the given equation:

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

`[H^+]=1* 10^(-4)M`

Thus concentration of hydrogen ions [H+] in a solution of pH = 4.0 is
`1* 10^(-4)M`