Gay Lussac’s of combining volumes states that gases react in simple ratio with one another and to volumes of the products provided that temperature and pressure remain constant. In this article, you will understand how to apply this law in calculation by studying the following examples below: 1. 2H 2 + O 2 → H 2 O In the reaction above, what volume of hydrogen would be left over when 300cm 3 of oxygen and hydrogen are exploded in a sealed tube? 1cm 3 of oxygen = 2cm 3 of hydrogen 300cm 3 of oxygen = 2 x 300 = 600cm 3 Volume of left over = 1000 – 600 = 400cm 3 2. Calculate the volume of carbon (II) oxide required to react with 40cm 3 of oxygen. 2CO + O 2 → 2CO 2 1cm 3 of oxygen = 2cm 3 of CO 40cm 3 of oxygen = 2 x 40 = 80cm 3 3. Calculate the volume of residual gases that would be produced when 100cm 3 of sulphur (IV) oxide reacts with 20cm 3 of oxygen 2SO 2 + O 2 → 2SO 3 1cm 3 of O 2 = 2cm 3 20cm 3 of O 2 = 2 x 20 = 40cm 3
In this qualitative analysis, we are going to review the possible qualitative analysis practical exam questions you are likely to expect in the coming NECO examination. You are expected to analyse the ions in the following compounds · Zinc trioxocarbonate IV (labelled X n ) watch video 1 · Aluminium chloride ( labelled Y n ) watch video 2 The reagents for the qualitative analysis of these compounds include · Dilute sodium hydroxide solution · Dilute aqueous ammonia · Dilute hydrochloric acid · Distilled water · Red and blue litmus paper · Barium chloride · Phenolphthalein · Calcium hydroxide · Methyl orange · One boiling tube · Filtration apparatus · Source of heat s/n Test Observation Inference A(I) X + dilute HCl, divide into two portions Effervescenc