A compound contains 3 200 % C , 9 100 % H and 9 200 % O . Its molecular weight is 144 . Choose the correct statement(s) :

Question

A compound contains 3 200 ​ % C , 9 100 ​ % H and 9 200 ​ % O . Its molecular weight is 144 . Choose the correct statement(s) :

TestHub · Accepted Answer

Given percentages: C = 66.67%, H = 11.11%, O = 22.22%

Taking 100 g of the compound:

Moles of C = $\frac{66.67}{12} = 5.55$

Moles of H = $\frac{11.11}{1} = 11.11$

Moles of O = $\frac{22.22}{16} = 1.39$

Dividing by the smallest number of moles (1.39):

Ratio of C : H : O = $\frac{5.55}{1.39} : \frac{11.11}{1.39} : \frac{1.39}{1.39} \approx 4 : 8 : 1$

Empirical formula = C₄H₈O

Empirical mass = $(4 \times 12) + (8 \times 1) + (1 \times 16) = 48 + 8 + 16 = 72$

Given molecular mass = 144

The value of $n$ is calculated as:

$n = \frac{M o l ec u l a r ma ss}{E m p i r i c a l ma ss} = \frac{144}{72} = 2$

Molecular formula = $(C_{4} H_{8} O)_{2} = C_{8} H_{16} O_{2}$ (B)

For the molecular formula C₈H₁₆O₂:

Total number of atoms = $8 + 16 + 2 = 26$

Percentage of Carbon (%C) = $\frac{N u mb ero f C a t o m s}{T o t a l a t o m s} \times 100 = \frac{8}{26} \times 100 \approx 30.77%$ (C)

Correct Answer: B, C

Chemistry - Mole Concept Question with Solution | TestHub