Starting with solid zinc 2 oxide describe how a solid sample of zinc 2 hydroxide can be prepared?

To prepare a solid sample of zinc 2 hydroxide from solid zinc 2 oxide, you would first need to react the zinc 2 oxide with a solution of a strong base, such as sodium hydroxide (NaOH).

The chemical equation for this reaction is:

ZnO + 2NaOH -> Zn(OH)2 + Na2O

In this reaction, the zinc 2 oxide reacts with the sodium hydroxide to form zinc 2 hydroxide and sodium oxide. The zinc 2 hydroxide will precipitate out of the solution as a solid.

To isolate the solid zinc 2 hydroxide, you would need to filter the solution to separate the solid from the liquid. The solid can then be washed with water to remove any impurities and dried to obtain a pure sample of zinc 2 hydroxide.

Step 1: Dissolve Zinc Oxide in Water

- Heat water to boiling.
- Slowly add zinc oxide powder to the boiling water while stirring.
- Continue adding zinc oxide until no more will dissolve.

Step 2: Filter the Solution

- Allow the solution to cool to room temperature.
- Filter the solution through a filter paper to remove any impurities.

Step 3: Add Sodium Hydroxide Solution

- Prepare a 1 M solution of sodium hydroxide (NaOH).
- Slowly add the NaOH solution to the filtered zinc oxide solution while stirring continuously.
- Continue adding NaOH until a white precipitate forms.

Step 4: Collect the Precipitate

- Filter the suspension to collect the white precipitate.
- Wash the precipitate thoroughly with distilled water to remove any impurities.

Step 5: Dry and Heat the Precipitate

- Dry the precipitate in an oven at 110-120°C overnight.
- Heat the dried precipitate in a crucible at 180-200°C for 2-3 hours to convert it to solid zinc hydroxide.

Reaction Equation:

ZnO + 2NaOH → Zn(OH)₂ + Na₂O