Question

pH is a logarithmic scale used to indicate the hydrogen ion concentration, [H+], of a solution: pH=−log[H+] Due to the autoionization of water, in any aqueous solution, the hydrogen ion concentration and the hydroxide ion concentration, [OH−], are related to each other by the Kw of water: Kw=[H+][OH−]=1.00×10−14 where 1.00×10−14 is the value at approximately 297 K. Based on this relation, the pH and pOH are also related to each other as 14.00=pH+pOH The temperature for each solution is carried out at approximately 297 K where Kw=1.00×10−14. Part A 0.35 g of hydrogen chloride (HCl) is dissolved in water to make 2.5 L of solution. What is the pH of the resulting hydrochloric acid solution?

Answer 1

Answer:

pH = 2,4

Explanation:

pH is defined as a measure of acidity or alkalinity of a solution based on H⁺ concentration

The HCl dissociates in water thus:

HCl → H⁺ + Cl⁻

That means that moles of HCl are the same than H⁺.

0,35gHCl$\frac{1mol}{36,46g}$ = 9,6x10⁻³ moles HCl ≡ moles H⁺

H⁺ molarity is: $\frac{9,6x10^{-3}moles}{2,5L}$ = 3,84x10⁻³M

As pH = -log [H⁺]

pH = 2,4

I hope it helps!