Question

how you can obtain pure samples from amixture corntaining ammonium chrolide, copperoxideand pttasium curbonate

Answer 1

-Place the mixture in a beaker and cover it with a watch glass. Heat the mixture. Ammonium chloride sublimes leaving a mixture of copper oxide and potassium carbonate in the beaker.
-Remove the watch glass and allow it to cool. Ammonium chloride deposits would be formed on the watch glass.
-Add water to the mixture of copper oxide and potassium carbonate in the beaker. Potassium carbonate dissolves leaving copper oxide at the bottom of the beaker.
-Filter the mixture to obtain copper oxide as a residue and potassium carbonate solution as a filtrate.
-Evaporate the filtrate to saturation and allow it to cool for potassium carbonate crystals to be formed.
-Wash the copper oxide residue with distilled water and dry it between the filter papers.