levo

Acids and Bases

The Ionic Product of Water and Strong Bases

  • 3 things to know
  • Papers 1 and 3

Overview

Kw, its value at 25°C, and using it to find the pH of a strong base.

What you need to know

Answer each one before you reveal it.

Your recallNot started
Key term

What is the pH of a 0.01 mol dm⁻³ solution of NaOH at 25°C?

Key term

What is the pH of a 0.05 mol dm⁻³ solution of Ba(OH)₂ at 25°C?

Key term

What is the ionic product of water?

Questions from this subtopic

Each one with the model answer underneath.

  1. 1

    What is the ionic product of water?

    Model answer

    The ionic product of water is the equilibrium constant for the dissociation of water into hydrogen ions and hydroxide ions.

  2. 2

    Write the expression for the ionic product of water, Kw.

    Model answer

    Kw = [H⁺][OH⁻]

  3. 3

    What is the value of Kw at 25°C?

    Model answer

    Kw = 1.00 × 10⁻¹⁴ mol² dm⁻⁶ at 25°C.

  4. 4

    What are the units of Kw?

    Model answer

    mol² dm⁻⁶

  5. 5

    In pure water at 25°C, what is the concentration of hydrogen ions?

    Model answer

    1.00 × 10⁻⁷ mol dm⁻³

  6. 6

    In pure water at 25°C, what is the concentration of hydroxide ions?

    Model answer

    1.00 × 10⁻⁷ mol dm⁻³

Other ways to work this

The same content, four other ways.

What is inside Levo

Six ways to work the same material.

1Closed book
2Open book
3Closed book

The 3-step method, run for you

Answer cold, learn it, then prove it stuck. Levo tracks the jump between your first attempt and your last.

Atomic Structure
Amount of Substance
Bonding
Energetics and Thermodynamics

Cram a whole paper in one sitting

Sort every topic into what you know and what you do not, then drill only the weak ones.

A atom.
nitrogencarbonsulfur

Blank Blitz makes facts automatic

Rapid timed gap-fills on the terms and numbers you need to recall without thinking.

AOxidation is the loss of electrons.
BReduction is the gain of electrons.
CAn oxidising agent is an electron acceptor.

Build It gets the exam shape right

Assemble a full-mark answer from its marking points, in the order an examiner wants them.

The sum of all mole fractions equals 1.
TrueFalse

Test It catches misconceptions

Spot the fault in a statement. The traps are the mistakes students actually make.

721941163128510

Brain Breaks between sessions

Short focus games to reset attention, so the next set lands better than the last.

Every question in Acids and Bases, on a schedule.

Attempt a question from memory, write the correct version, then attempt it again. Levo records the jump between your first attempt and your last, and brings each question back on the day you are due to forget it.

Or £46 a year, about £3.83 a month. Cancel anytime.