There are a few different ways to separate potassium dichromate from water. One common method is to use evaporation. This involves heating the solution until the water evaporates, leaving behind the potassium dichromate. Another method is to use filtration. This involves passing the solution through a filter paper, which will trap the potassium dichromate crystals while allowing the water to pass through. Finally, you can also use precipitation. This involves adding a chemical to the solution that will cause the potassium dichromate to form a solid precipitate, which can then be filtered out.

Here are the steps for each method:

Evaporation:

1. Heat the solution until the water evaporates.

2. As the water evaporates, the potassium dichromate crystals will start to form on the sides of the container.

3. Once all of the water has evaporated, the potassium dichromate crystals will be left behind.

Filtration:

1. Place a filter paper in a funnel.

2. Pour the solution through the funnel.

3. The potassium dichromate crystals will be trapped on the filter paper, while the water will pass through.

4. Rinse the filter paper with water to remove any remaining potassium dichromate crystals.

5. Dry the filter paper with the potassium dichromate crystals.

Precipitation:

1. Add a chemical to the solution that will cause the potassium dichromate to form a solid precipitate. Some common precipitating agents include barium chloride, lead nitrate, and silver nitrate.

2. Stir the solution until the precipitate has formed.

3. Filter the solution to remove the precipitate.

4. Wash the precipitate with water to remove any remaining impurities.

5. Dry the precipitate.