Skip to main content

Back to the full dot-point answer

QLDChemistryQuick questions

Unit 3: Equilibrium, acids and redox reactions

Quick questions on pH, Kw and the self-ionisation of water (QCE Chemistry Unit 3)

6short Q&A pairs drawn directly from our worked dot-point answer. For full context and worked exam questions, read the parent dot-point page.

What is the self-ionisation of water?
Show answer
Two water molecules can transfer a proton:
What are strong acid pH calculations?
Show answer
For monoprotic strong acids (HCl, HBr, HI, HNO3, HClO4), [H3O+] = [acid] for any concentration above about 10^-6 mol/L.
What are strong base pH calculations?
Show answer
For sodium hydroxide and other group 1 hydroxides, [OH-] = [base]. Calculate pOH then convert to pH.
What is q1?
Show answer
Write the expression for the autoionisation constant of water and its value at 25∘C25^{\circ}\text{C}. [2 marks]
What is q2?
Show answer
A NaOH solution has pH=12.30\text{pH} = 12.30. Calculate [OH−][\text{OH}^-] and the original concentration. [3 marks]
What is q3?
Show answer
Kw=1.47×10−14K_w = 1.47 \times 10^{-14} at 30∘C30^{\circ}\text{C}. (a) Calculate pH\text{pH} of pure water at 30∘C30^{\circ}\text{C}. (b) State whether it is still neutral.

Have a question we have not covered?

This dot-point answer is short enough that we have not extracted many short questions yet. Read the full dot-point answer or ask Mo, our study assistant, in the chat for follow ups.

All ChemistryQ&A pages