Skip to content

Course home

Sign up

Acids and bases (A-level only)

EasyMedium
1234567891011121314151617181920212223242526272829303132333435363738394041424344454647484950515253545556575859
Question 17

Values of the ionic product of water (KwK_wKw​) at different temperatures are given:

  • Kw=3.60×10−15 mol2 dm−6K_w = 3.60 \times 10^{-15} \text{ mol}^2 \text{ dm}^{-6}Kw​=3.60×10−15 mol2 dm−6 at 10 ∘C10\ ^\circ\text{C}10 ∘C
  • Kw=1.00×10−14 mol2 dm−6K_w = 1.00 \times 10^{-14} \text{ mol}^2 \text{ dm}^{-6}Kw​=1.00×10−14 mol2 dm−6 at 25 ∘C25\ ^\circ\text{C}25 ∘C

Which statement is correct?

A

The concentration of hydrogen ions in pure water at 10 ∘C10\ ^\circ\text{C}10 ∘C is 6.00×10−8 mol dm−36.00 \times 10^{-8} \text{ mol dm}^{-3}6.00×10−8 mol dm−3

B

The dissociation of water into ions is an exothermic process.

C

The pH of pure water is the same at 25 ∘C25\ ^\circ\text{C}25 ∘C and at 10 ∘C10\ ^\circ\text{C}10 ∘C

D

Water becomes less acidic as the temperature is raised.

Markscheme

Acids and bases (A-level only) Questions

  1. A Level
  2. /Chemistry
  3. /Acids and bases (A-level only)

77 exam-style questions on AQA A Level Chemistry Acids and bases (A-level only), covering Brønsted–Lowry acid–base equilibria in aqueous solution (A-level only), Definition and determination of pH (A-level only), The ionic product of water, $K_w$ (A-level only), Weak acids and bases $K_a$ for weak acids (A-level only), pH curves, titrations and indicators (A-level only), and Buffer action (A-level only). Each one has a worked solution and a mark scheme showing where the marks go.

Question bank