Chemistry, asked by nandanashibu, 10 months ago

an organic compound contains c =54.3% h= 9%. the molecular mass of the compound is 88u. what is molecular formula

Answers

Answered by ShuchiRecites
13

C₂H₄O is ths compound

Step - by - step Explanation: C = 54.3%, H = 9% then O = 100% - (54.3 + 9)% = 36.7%.

Molecular Mass = 88 u

→ Carbon = 54.3/100 × 88u = 47.784

→ Hydrogen = 9/100 × 88u = 7.92

→ Oxygen = 36.7/100 × 88u = 32.296

Moles of

→ Carbon = 47.784/12 = 3.982 or 4

→ Hydrogen = 7.92/1 = 7.92 or 8

→ Oxygen = 32.296/16 = 2.0185 or 2

Molecular Formula

→ 3.982:7.92:2.0185 or 4:8:2

→ 2:4:1

Hence Compound is C₂H₄O

Answered by Anonymous
0

Question :

The molar mass of a compound is 88 g/mol. It contains 54.53% carbon, 9.15% hydrogen and 36.32% oxygen. What is the molecular formula of the compound?

Answer :

♣ In this case, a molar mass of   88g mol ⁻¹ tells you that one mole of this compound has a mass of  88 g

You can convert between percentages and grams by using a sample of  

100 g.

Then we have :

$\displaystyle\text{For C: }\ {88}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}\cdot\frac{\text{54.53 g C}}{{{100}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}}}=\text{47.986 g C}$

$\displaystyle\text{For H: }\ {88}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}\cdot\frac{\text{9.15 g H}}{{{100}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}}}=\text{8.052 g H}$

$\displaystyle\text{For O: }\ {88}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}\cdot\frac{\text{36.32 g O}}{{{100}{\color{red}{\cancel{{{\color{black}{\text{g sample}}}}}}}}}=\text{31.962 g O}$

→ Use the molar mass of each element to determine how many moles of each are present in one mole of this compound

$\displaystyle\text{For C: }\ {47.986}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}\cdot\frac{\text{1 mole C}}{{{12.011}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}}}={3.995}\approx\text{4 moles C}$

$\displaystyle\text{For H: }\ {8.052}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}\cdot\frac{\text{1 mole H}}{{{1.00794}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}}}={7.990}\approx\text{8 moles H}$

$\displaystyle\text{For O: }\ {31.962}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}\cdot\frac{\text{1 mole O}}{{{15.9994}{\color{red}{\cancel{{{\color{black}{\text{g}}}}}}}}}={1.998}\approx\text{2 moles O}$

We can say that one molecule of the compound will contain

  • 4 atoms of carbon
  • 8 atoms of hydrogen
  • 2 atoms of oxygen

Therefore, the compound's molecular formula : $\displaystyle{\color{green}{\text{C}_{{4}}\text{H}_{{8}}\text{O}_{{2}}}}$

Regards :)

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