Question

How many moles of HCl are found in 500mL of HCl solution with pH of 3​

Answer 1

Number of moles = 0.0005 mol.

Step-by-step explanation:

Given data:

pH = 3

Volume of solution = 500 mL

Number of moles = ?

Solution:

HCl dissociate to gives H⁺ and Cl⁻

HCl → H⁺ + Cl⁻

It is known that,

pH = -log [H⁺]

3 = -log [H⁺]

[H⁺] = 10⁻³ M

[H⁺] = 0.001 M

Number of moles of HCl:

Molarity = number of moles / Volume in litter

Number of moles = Molarity × Volume in litter

Number of moles = 0.001 mol/L × 0.5 L

Number of moles = 0.0005 mol