OmniLab Observation guide

For chemistry students · 5 minute read

What precipitate forms from copper(II) sulfate and potassium hydroxide?

Copper(II) sulfate and potassium hydroxide form copper(II) hydroxide, an insoluble blue precipitate. Potassium and sulfate ions remain dissolved in the solution.

Try the blue precipitate setup

The exact supported pair opens in a beaker. Nothing runs until you select Analyze.

The OmniLab virtual chemistry workspace with a beaker area and reaction analysis panel
Prepared beaker
CuSO4 KOH
Burner off · Analysis waits for you
A beaker is prepared with Copper(II) sulfate and Potassium hydroxide. The burner stays off, and you decide when to analyze.

Supported prediction

CuSO4(aq) + 2KOH(aq) -> Cu(OH)2(s) + K2SO4(aq)

What the equation means

Copper(II) sulfate and potassium hydroxide undergo a double displacement reaction. Insoluble copper(II) hydroxide forms as a blue precipitate while potassium sulfate remains in solution. Two hydroxide ions are required for each copper(II) ion.

Expected observation

A blue copper(II) hydroxide precipitate

OmniLab shows a bounded blue precipitate cue inside the beaker to represent the expected copper(II) hydroxide solid.

Net ionic equation

Which ions actually form the precipitate?

Copper(II) ions combine with hydroxide ions because copper(II) hydroxide is insoluble in water. Potassium and sulfate ions do not form the solid, so they cancel from the complete ionic equation.

Particles that change Cu2+(aq) + 2OH-(aq) -> Cu(OH)2(s)

Spectator ions: K+(aq) and SO4^2-(aq)

  1. 01

    Split the soluble reactants into ions

    CuSO4 provides Cu2+ and SO4^2-. Each KOH provides K+ and OH-.

  2. 02

    Identify the insoluble product

    Cu2+ combines with two OH- ions to form solid Cu(OH)2, the blue precipitate.

  3. 03

    Cancel the spectator ions

    K+ and SO4^2- remain aqueous on both sides, leaving the net ionic equation for precipitation.

Three safety notes

Read these before any physical experiment

  1. 01

    Wear splash goggles and chemical-resistant gloves.

  2. 02

    Avoid skin contact with copper sulfate and potassium hydroxide.

  3. 03

    Collect copper-containing waste for proper disposal.

Keep exploring

Connect this observation to another reaction

These guides use the same pattern: predict the equation, identify the visible cue, then check what the virtual model leaves out.

See how the full virtual lab works