Question

A compound consists of 40.00% C, 6.713% H and 53.28% O on a mass basis and has a molar mass of about 180 g/mole. Determine the molecular formula of the compound.

Answer 1

Answer:

The molecular formula of the compound is $C_6H_{12}O_6$.

Explanation:

Let the molecular formula of the compound is $C_xH_{y}O_z$.in

Molar mass of compound = 180 g/mol

Number of carbon atom = x

Number of hydrogen atom = y

Number of oxygen atom = z

Atomic mass of carbon = 12 g/mol

Atomic mass of hydrogen = 1 g/mol

Atomic mass of oxygen = 16 g/mol

Percentage of element in compound :

$=\frac{\text{number of atoms}\times \text{Atomic mass}}{\text{molar mas of compound}}\times 100$

Carbon :

$40.00\%\%=\frac{x\times 12g/mol}{180 g/mol}\times 100$

x = 46

Hydrogen :

$6.713\%=\frac{y\times 1 g/mol}{180 g/mol}\times 100$

y = 12

Oxygen:

$53.28\%=\frac{z\times 16 g/mol}{180 g/mol}\times 100$

z = 5.99 ≈ 6

The molecular formula of the compound is $C_6H_{12}O_6$.