Answer:
Molecular formula = C₂H₄Cl₂
Explanation:
Molecular formula:
Molecular formula consist of symbols of elements present in compound with numbers of atoms of each element in subscript.
Empirical formula:
It is the simplest formula gives the ratio of atoms of different elements in small whole number .
Given data:
Percentage of hydrogen = 4.07%
Percentage of Cl = 71.65%
Percentage of carbon = 24.27%
Molar mass = 99 g/mol
Molecular formula = ?
Solution:
Number of gram atoms of H = 4.07 / 1.01 = 4.0
Number of gram atoms of Cl = 71.65 / 35.5 = 2.0
Number of gram atoms of C = 24.27 / 12 = 2.0
Atomic ratio:
H : C : Cl
4/2 : 2/2 : 2/2
2 : 1 : 1
C : H : Cl = 1 : 2 : 1
Empirical formula is CH₂Cl.
Molecular formula:
Molecular formula = n (empirical formula)
n = molar mass of compound / empirical formula mass
Empirical formula mass = 12+1×2+ 35.5 = 49.5
n = 99/49.5
n = 2
Molecular formula = n (empirical formula)
Molecular formula = 2 ( CH₂Cl)
Molecular formula = C₂H₄Cl₂
