Question

(i) What mass of oxygen is required to react completely with\[24g\] of \[C{H_4}\] in the following reaction?
\[C{H_4}_{\left( g \right)} + 2{O_2}_{\left( g \right)} \to C{O_2}_{\left( g \right)} + 2{H_2}{O_{\left( L \right)}}\]
(ii) How much mass of \[C{H_4}\] would react with \[96g\] of oxygen?

Answer 1

Hint: Here one mole of methane is reacted with two moles of oxygen and one moles of carbon dioxide and two moles of water molecules. Methane is a chemical compound having the chemical formula, \[C{H_4}\] with molecular mass \[16g/mol\]. Here the carbon is bonded with four hydrogen atoms by a single bond. The methane is the simplest alkane and it is used to prepare the chemicals and it is also used as a constituent of the fuel.

Complete answer:
(i) From the given reaction, we can say that one mole of methane requires two mol of oxygen to produce one mole of carbon dioxide and two moles of water molecules.
Molecular weight of methane\[ = 16g\]
Number of moles of methane\[ = \dfrac{{given mass}}{{molar mass}}\]
Given mass is equal to \[24g\]. Hence,
\[number of moles = \dfrac{{24}}{{16}} = 1.5mol\]
According to the chemical reaction, one mole of carbon dioxide requires two moles of oxygen. Hence,
The mass of oxygen is required to react completely with \[24g\] of \[C{H_4}\]\[ = 2 \times 1.5\]
                                                                                                                         \[ = 3\,mol\]
\[3\,mole = 16 \times 3 = 48g\]
Therefore, \[48g\] of oxygen is required to react completely with \[24g\] of \[C{H_4}\] is equal to \[48g\].
(ii) One mole of methane reacts with two moles of oxygen.
Number of moles\[ = \dfrac{{given mass}}{{molar mass}}\]
Given mass is equal to \[96g\] and molar mass of oxygen molecules is equal to\[32g\]. Hence, one mole of oxygen requires \[\dfrac{1}{2}\] moles of methane. Which means, \[32g\] of oxygen requires \[16g\] of methane. Therefore,
Mass of \[C{H_4}\] would react with \[96g\] of oxygen\[ = \dfrac{{16}}{{32}} \times 96\]
                                                                               \[ = 48gofC{H_4}\]
Mass of \[C{H_4}\] would react with \[96g\] of oxygen is \[48g\].

Note:
We need to know that when the methane is reacted with oxygen there is a formation of carbon dioxide and water. The number of moles can be found by dividing given mass with molecular mass. The molecular weight is equal to the sum of atomic mass of every atom which is present in a compound or the molecule. And the molecular weight is another term of molar mass which is used for the molecular compounds, and it will not depend on the size of the sample.