Acid–base Equilibria

Question

If the ionic product of water increases with temperature, which statement is correct?

RankGuru · Accepted Answer

1. **Equilibrium**: $H_2O \rightleftharpoons H^+ + OH^-$. This process is **endothermic** (bonds must be broken).
2. **Le Chatelier's Principle**: As $T$ increases, equilibrium shifts right, so **$K_w$ increases**.
3. **Standard Conditions**: At $25^\circ C, K_w = 10^{-14} \implies [H^+] = 10^{-7} \implies pH = 7$.
4. **High Temperature**: At $60^\circ C, K_w \approx 10^{-13}$.
5. **Neutrality**: For water to be neutral, $[H^+] = [OH^-] = \sqrt{K_w}$.
6. **Calculated pH**: In neutral water at $60^\circ C$, $[H^+] = 10^{-6.5} \implies pH = 6.5$.
7. **Result**: Water is still neutral, but its **neutral $pH$ value has decreased**.

Rank Guru

Acid–base Equilibria

Select the correct option:

Solution

🔒 Solution Hidden from View

More acid–base equilibria Practice Questions

Which change increases the pH of an acetic acid/sodium acetate buffer the most?

The percent dissociation of a 1.0×10⁻³ M solution of a weak monoprotic acid (Ka = 1.0×10⁻⁵) is appro...

Calculate [H+] (in mol L⁻¹) after mixing 25 mL of 0.040 M HCl with 75 mL of water (assume volumes ad...

The conjugate acid of (CH3)3 N is:

Which factor most strongly determines whether an amphoteric species acts as an acid or a base in wat...

A 0.10 M solution of a weak base B has Kb = 2.5×10⁻⁴. The pOH of the solution is approximately:

About This Question