A hydrocarbon is burnt completely to give 3.447g of
C
O
2
and 1.647g of
H
2
O
. What is the empirical formula ?

The answer to your question is C₃H₇

Explanation:

Data

mass of CO₂ = 3.447 g

mass of H₂ = 1.647 g

Empirical formula = ?

Process

1.- Write the chemical reaction

                       CxHy + O₂   ⇒     CO₂   +   H₂O

2.- Calculate the mass and moles of carbon

                      44 g of CO₂ 12 g of C

                       3.447 g  of CO₂  x

                       x = (3.447 x 12) / 44

                       x = 0.94 g of C

                       12 g of C 1 mol

                       0.94 g of C  x

                       x = 0.0783 moles of C

3.- Calculate the grams and moles of H

                       18 g of H₂O  2 g of H

                       1.647 g of H₂O  x

                        x = (1.647 x 2)/18

                        x = 0.183 g of H

                       1 g of H     1 mol

                        0.183 g      x

                        x = (0.183 x 1)/1

                        x = 0.183 mol of H

4.- Divide by the lowest number of moles

Carbon = 0.0783 /0.0783 = 1

Hydrogen = 0.183 / 0.0783 =2.3

5.- Write the empirical formula

                          C₁H₂.₃ = 3C₁H₂.₃ = C₃H₇

c. is the answer

by love gaming

hydrocarbons are organic compounds that contain only hydrogens and carbons. they can be saturated (those which contain only carbon-carbon single bonds) or unsaturated (those which contain carbon-carbon double or triple bonds) in nature. hydrocarbons can undergo several reactions like substitution, elimination etc.  

on substituting one or more hydrogen atoms in hydrocarbon it results in the formation of haloalkane. as the halogen atoms are large compared to the carbon and hydrogen atoms, due to which the molecular weight increases and the bond become polar because of presence electronegative halogen atom and results in the increase in boiling point of the haloalkane.

thus, the correct option is (b) that is the boiling point of the new compound increases on substituting a hydrogen atom with a halogen in a hydrocarbon.