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In a solution prepared by dissolving 1.26 g of pure nitric acid in water to give 0.475 L of solution, what is the pH to three decimal places?

a) 1.943
b) 2.345
c) 1.678
d) 1.523

1 Answer

4 votes

Final answer:

The pH of the solution prepared by dissolving 1.26 g of pure nitric acid in water to give 0.475 L of solution is approximately 1.377. None of the choices are correct.

Step-by-step explanation:

To determine the pH of the solution, we need to calculate the concentration of hydronium ions (H3O+). Given that 1.26 g of pure nitric acid is dissolved in 0.475 L of solution, we can calculate the molarity of the solution:

Molarity (M) = moles of solute / volume of solution (L)

Moles of nitric acid = 1.26 g / molar mass of nitric acid

= 1.26 g / 63.01 g/mol

= 0.02 mol

Molarity = 0.02 mol / 0.475 L

= 0.0421 M

Since nitric acid is a strong acid, it completely ionizes in water:

HNO3(aq) → H+(aq) + NO3-(aq)

Therefore, the concentration of H3O+ ions is equal to the molarity of the solution.

pH = -log[H3O+]

pH = -log(0.0421)

pH = 1.377 (rounded to three decimal places)

Therefore the correct answer is none of the options.

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