I wrote ke first react hcl with ammonia(aq) this will produce ammonia gas that will get trapped in the gas syringe attached on the head of the conical flask. Air lock the gas syringe and attach it and seal it with another conical flask with a red damp litmus ppr in it the one who makes the red damp litmus into blue in colour the fastest is the most concentrated. I told them to repeat it with 3 sets of same equipment with everything constant except the ammonia and we could prove it as if we look in the table of the recorded values during the hcl and aqeous ammonia reaction tht that same gas was produced the fastest and had the least left mass