Question

What molar concentration of hydrochloric acid (HCl) is needed to prepare a disinfectant solution with a pH

Answer 1

The correct approach is "3.1×10⁻³ M".

Step-by-step explanation:

As we know,

`pH=-log[H_(3)O^+]`

`pH=2.5`

`[H_(3)O]^+= \ ?`

Now,

⇒
`-log[H_(3)O]^+=2.5`

⇒
`[H_(3)O]^+=10^(-2.5)`

⇒
`=3.1* 10^(-3) \ M`

So that the needed molar concentration of HCL will be:

=
`3.1* 10^(-3) \ M`