Answer:
The correct formula of dioxane is C₄H₈O₂.
Step-by-step explanation:
Given data:
mass of dioxane= 2.23 g
mass of water = 1.802 g
mass of carbon dioxide = 4.401 g
molar mass of dioxane = 88.1 g / mol
Molecular formula of dioxane = ?
Solution:
percentage of carbon = (4.401 g/2.23 g ) × (12 /44) × 100
= (1.98 × 0.273) × 100 = 54.1
percentage of hydrogen = (1.802 g/ 2.23 g) × (2.016 /18.016) × 100
= (0.81 × 0.112) × 100 = 9.072
percentage of oxygen = 100 - (54.1 + 9.072)
= 100 - 63.172 = 36.828
Now we will determine the number of grams atoms of carbon, hydrogen and oxygen.
No. of gram atoms of carbon = 54.1 /12 = 4.51
No. of gram atoms of hydrogen = 9.072 / 1.008 = 9
No. of gram atoms of oxygen = 36.828 / 16 = 2.302
Atomic ratio:
C :H :O 4.51/ 2.302 : 9 / 2.302 : 2.302 /2.302
C :H :O 2 : 4 : 1
Molecular formula:
Molecular formula = n × (empirical formula)
n = molar mass of compound / empirical formula mass
empirical formula mass= 2 × 12 + 4 × 1.008 + 1 × 16
empirical formula mass= 24+ 4.032 +16 = 44.032
n = 88.1 / 44.032 = 2
Molecular formula = n × (empirical formula)
Molecular formula = 2 × (C₂H₄O)
Molecular formula = C₄H₈O₂