Answer:
Empirical formula is C₂H₃O, and molecular formula is C₄H₆O₂
Explanation:
W(C) = 55,8%
W(H) = 7,03%
W(O) = 37,2%
m(tot.) = 1,5 g
First, you need to calculate mass of every element:
m(x) = m(tot.) × W(x), and you get:
m(C) = 0,837 g
m(H) = 0,105 g
m(O) = 0,558 g.
Next step is to calculate moles of every element end compare them.
n(x) = m(x)/ Ar(x)
n(C) = 0,07
n(H) = 0,104
n(O) = 0,035.
n(C) : n(H) : n(O) = 2 : 3 : 1, so empirical formula is:
C₂H₃O
Number of each atom in molecular formula (a) is calculated by
a = N(x) = (W(x) × Mr(compound)) / Ar(x) (a)
Mr(compound) is calculated from the ideal gas law:
p × V = n × R ×T
p × V = m/Mr × R ×T
Mr =(R × T × m)/ p × V
Mr = 89 g mole⁻¹
Now, we go back in equation a and calculate number of each atom in molecular formula (a):
a(N(C)) = 4
b(N(H)) = 6
c(N(O)) = 2
So, molecular formula is C₄H₆O₂
