When solutions are mixed together, precipitates sometimes form.
Copper(II) hydroxide is an insoluble compound. It is formed as a precipitate when solutions of the soluble compounds copper(II) chloride and sodium hydroxide are mixed.
When solutions of the soluble compounds potassium nitrate and sodium carbonate are mixed, no precipitate is formed.
Complete the table to show the results of mixing solutions of some compounds.
| sodium hydroxide solution | sodium carbonate solution | |
|---|---|---|
| copper(II) chloride solution | precipitate of copper(II) hydroxide | ............................................................\text{............................................................}............................................................ |
| potassium nitrate solution | ............................................................\text{............................................................}............................................................ | no precipitate |
| magnesium chloride solution | precipitate of magnesium hydroxide | ............................................................\text{............................................................}............................................................ |
When solutions of silver nitrate and sodium chloride are mixed, a template of silver chloride and a solution of sodium nitrate are produced.
The equation for the reaction is:
AgNO3(..........)+NaCl(..........)→AgCl(..........)+NaNO3(..........) \text{AgNO}_3(\text{..........}) + \text{NaCl}(\text{..........}) \rightarrow \text{AgCl}(\text{..........}) + \text{NaNO}_3(\text{..........}) AgNO3(..........)+NaCl(..........)→AgCl(..........)+NaNO3(..........)Complete the equation by inserting the state symbols.
In order to prepare a pure, dry sample of silver chloride, a student took the mixture produced in part (b). She then:
Why did the student filter the mixture?
Why did she wash the solid residue?
Why is it better to use distilled water rather than tap water to wash the solid residue?
Why did she leave the solid in a warm place?
