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...
The calculation of limiting reagents and excess reagents is a real-life application of the stoichiometric relationship between reactants and products. Limiting Reagent : this is the reagent which gets consumed entirely in the chemical reaction. It determines how long a chemical reaction will last or the amount of products to be produced. In other words, the limiting reagent or reactant stops the chemical reaction. Excess Reagent : this is the reactant that could continue to react if the other reactant is still available for the reaction. Let us look at this example, and assume that all the requirements of producing a tricycle are three wheels and a wheel steering and a tricycle company has 600 wheels and 250 wheel-steerings for the production of tricycles. Which of the materials will finish first and how many of the other materials will be left over? 3 wheels + 1 steering = 1tricycle The first thing to do is to find the number of tricycles th...