d Ammonia i Put a mixture of calcium hydroxide and ammonium chloride into a testtube to a depth of 4 cm Fill a Utube with lumps of calcium oxide mixed with cotton wool The cotton wool is to prevent blocking of the tube Gently heat the testtube The calcium oxide dries the ammonia gas Test whether the receiver testtube is full by holding a piece of red litmus paper at the opening Collect test tubes of ammonia and cork them The method of collection illustrates that ammonia gas is lighter than air ii Fill a flask with ammonia Fit a cork and tube into the flask as shown The tube should have been drawn out into a jet Warm the flask gently to expand the gas and then hold the flask upside down with the tube in the water Water will spray into the flask from the jet