Question

The pH of a solution is 1.20. What is the [H3O+] for the solution?

1.58 × 10−2 M
6.31 × 10−2 M
1.58 × 101 M
6.31 × 101 M

Answer 1

`6.31*10^(-2)`

Step-by-step explanation:

Hello! To calculate the pH we have the following formula:

ph = -log [H3O +]

In this case we have the pH value so the formula is

[H3O +] =
`10^(-pH)`

[H3O +] =
`10^(-1.2)`

We use the inverse of the log

[H3O +] =
`6.31*10^(-2)`

So the correct answer is
`6.31*10^(-2)`

Answer 2

[H₃O⁺] = 6.31 x 10⁻² mol·L⁻¹

Step-by-step explanation:

pH = -log[H₃O⁺], so
`[\text{H}_(3)\text{O}^(+)] = 10^{- \text{pH}} \text{ mol/L}`

`[\text{H}_(3)\text{O}^(+)] = 10^(-1.20)\text{ mol/L} = 6.31 * 10^(-2)\text{ mol/L}`