Question

3. Calculate the molarity of the HCI solution if 0.074 mol of HCl is dissolved in water to

make 2000 mL of the solution. Also calculate the pH of this solution. Hint: In case of

strong acids the [H3O+] is same as the molarity of acid solution.

Answer 1

Molarity = 0.037 M

pH = 1.43

Step-by-step explanation:

First, you need to calculate the molarity. After converting mL to L, you can plug the values into the molarity equation and simplify.

2,000 mL / 1,000 = 2 L

Molarity (M) = moles / volume (L)

Molarity = 0.074 moles / 2 L

Molarity = 0.037 M

You can plug the molarity of the hydrogen ion into the pH equation to find the pH. Remember that H₃O⁺ and H⁺ can be considered the same thing. Since HCl dissociates into just one H⁺ and one Cl⁻, the molarity of the HCl solution is the same as the molarity of the H⁺.

pH = -log[H⁺]

pH = -log[0.037]

pH = 1.43