No products in the cart.

A hydrocarbon contains 85.7% C. If …

CBSE, JEE, NEET, CUET

CBSE, JEE, NEET, CUET

Question Bank, Mock Tests, Exam Papers

NCERT Solutions, Sample Papers, Notes, Videos

A hydrocarbon contains 85.7% C. If 42 mg of the compound contains 3.01X10*20 molecules, what is the molecular formula of the compound?
  • 1 answers

Gaurav Seth 4 years, 10 months ago

Mass of Compound = 42 mg = 42 x 10-3 g 

6.022 x 1023 molecules of compound = 1 mole
3.01 x 1020 molecules = (​3.01 x 1020 ) / (6.022 x 1023 )  =  0.5 x 10-3 moles of compound

Molar mass of the compound =  Mass /No. of moles  = 42 x 10-3 g / 0.5 x 10-3 = 84 g/mol

Mass of Carbon in 1 mole of Compound = 85.7/100 x 84  g/mol = 71.98 = 72 g/ mol of C

Mass of H in 1 mole = (14.3/100) x 84 = 12.012g /mol of H

No. of C atoms = 72 / 12 = 6
No. of H atoms = 12.012 /1 = 12

Therefore the formula of the compound is C6H12.

http://mycbseguide.com/examin8/

Related Questions

74 g of calcium hydroxide Ca(OH)2 in 1 liter
  • 1 answers

myCBSEguide App

myCBSEguide

Trusted by 1 Crore+ Students

Test Generator

Test Generator

Create papers online. It's FREE.

CUET Mock Tests

CUET Mock Tests

75,000+ questions to practice only on myCBSEguide app

Download myCBSEguide App