Question

An organic compound contains 69% carbon, 4.8% hydrogen and the remaining is oxygen. Calculate the mass of carbon dioxide produced when $0.20g$ of substance is subjected to combustion.
A.$0.40g$
B.$0.50g$
C.$0.60g$
D.$0.70g$

Answer 1

When a substance undergoes the process of combustion, it actually reacts with molecular oxygen in order to form corresponding products.
-Organic compounds, like hydrocarbons when undergoing the process of combustion, they form water and carbon dioxide.

Complete step by step answer:
Qualitative analysis is used to analyse the species present in a given compound . This analysis is more focused on the estimation of which element or ion are present in the compound . There are several methods used to analyse organic compounds such as the kjeldahl method etc .
Combustion is the process in which substances react rapidly with oxygen and give off heat . The reactant present is called fuel and oxygen is called oxidizer . combustion is easily related to burning of substance.
Combustion of organic compounds in presence of oxygen gives energy , carbon dioxide and water vapour.mainly , the combustion of hydrocarbon the main constituent of product are water vapour and carbon dioxide .
Now, comes to the solution part;
Given, percentage of carbon in organic compound present in sample $= 69\%$
$\Rightarrow$ $100g$ of organic compound contains $69\%$ of carbon .
Then , $0.2g$ of organic compound will contain $= 69 \times 0.2/100$ $= 0.138g$ of carbon.
We know , molecular of carbon dioxide $C{O_2} = 44g$
$\Rightarrow 12g$ of carbon is contained in $44g$ of $C{O_2}$
$\because 0.138g$ carbon will contain the amount of carbon we get by multiplying the mass of carbon in the organic compound with the molecular mass of the carbon, present per twelve gram of carbon. This can be mathematically calculated as $= 44 \times 0.138/12$ $= 0.506g$ of carbon
Thus, $0.506g$ of $C{O_2}$ will be produced on complete combustion of $0.2g$ of an organic compound .
Hence, option B is the correct option.

Note: When a hydrocarbon undergoes the process of combustion, it always gets converted to water and carbon dioxide, this is because the molecules of hydrocarbon contain hydrogen and carbon along with oxygen in case of carbonyl compounds. And the simplest molecules which could be produced by breaking of the bonds between these three elements, is carbon dioxide and water.