How many moles of hydrogen ions are present in a 2L solution with a pH of 2.75​

We are given:

Volume = 2 L

pH = 2.75

Finding the concentration required:

we know that pH is just the negative log of the hydrogen ion concentration

pH = -log[H⁺]

we are given that the pH is 2.75

2.75 = -log[H⁺]

log[H⁺] = -2.75                         [multiplying both sides by -1]

[H⁺] = 1.78 * 10⁻³ Molar

Number of moles of Hydrogen ions:

[H⁺] = 1.78 * 10⁻³ Molar

which means that there are 1.78 * 10⁻³ moles of hydrogen ions in 1 liter solution

1.78 * 10⁻³ moles / L

multiplying and dividing by 2, we get:

3.56 * 10⁻³ moles / 2 L

Hence we need 3.56 * 10⁻³ moles of hydrogen ions