Question

A scientist observes that after mixing a solid powder into water, the pH of the newly formed solution is 2.7. What can he infer from this observation?

The solution contains an indicator that has a pH of 2.7.

The solid powder contained hydrogen ions.

The pH indicator was used incorrectly.

The powder increased the hydrogen ion concentration of the solution.

Answer 1

Answer: The correct answer is' The powder increased the hydrogen ion concentration of the solution'.

Step-by-step explanation:

The pH abbreviated as power of hydrogen is defined as negative logarithm of
`H^+` ion in the solution.

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

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

`[H^+]=0.00199 M`

Whereas
`H^+` concentration in impure water is
`1* 10^{-7 M`

The solution with pH value 2.7 was formed when solid powder was mixed into water which means that solid powder has increased the
`H^+` concentration in the water.

Answer 2

The correct answer is
The powder increased the hydrogen ion concentration of the solution.

This means that the powder turned water into a more acidic substance since water's pH factor is 7, and things under 7 are acids.