Question

A 1.0 mole sample of HN03 is added to water. The final volume of the solution is 1.5 L in the final temperature of the solution is 25°C. Calculate the pH.

Answer 1

To find the pH of the solution, we first need to calculate the molarity of the HNO3 solution after it is added to the water.

Given:
Initial moles of HNO3 = 1.0 mol
Final volume of solution = 1.5 L

Molarity (M) = moles of solute / volume of solution (in L)
Molarity = 1.0 mol / 1.5 L
Molarity = 0.67 M

Now, we can calculate the pH of the solution using the formula:
pH = -log[H+]

Since HNO3 is a strong acid, it completely dissociates in water to produce H+ ions:
HNO3 → H+ + NO3-

Therefore, the concentration of H+ ions in the solution is equal to the molarity of the HNO3 solution:
[H+] = 0.67 M

pH = -log(0.67)
pH ≈ -log(0.67)
pH ≈ -(-0.173)
pH ≈ 0.173

Therefore, the pH of the solution after adding 1.0 mole of HNO3 to water is approximately 0.173.