molecular formula of the compound

Chemistry and homework help forum.

Organic Chemistry, Analytical Chemistry, Biochemistry, Physical Chemistry, Computational Chemistry, Theoretical Chemistry, High School Chemistry, Colledge Chemistry and University Chemistry Forum.

Share your chemistry ideas, discuss chemical problems, ask for help with scientific chemistry questions, inspire others by your chemistry vision!

Please feel free to start a scientific chemistry discussion here!

Discuss chemistry homework problems with experts!

Ask for help with chemical questions and help others with your chemistry knowledge!

Moderators: Xen, expert, ChenBeier

Post Reply
yon
Jr. Member
Jr. Member
Posts: 6
Joined: Thu Nov 30, 2006 10:10 am
Location: parker,co

molecular formula of the compound

Post by yon »

here are the problems---

A compound analyzes to be 37.5% C, 12.5% H, and 50.0% O. The molecular mass of the compound is 93.0. What is the molecular formula of the compound? (Type your answer using the format CH4 for CH4. Keep the elements in the order given.)




--------------------------------------------------------------------------------

40.
the composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. Its molecular mass is 162. What is its molecular formula? (Type your answer using the format CH4 for CH4. Keep the elements in the order given.)



plz show how u did the problems
let us just live in peace
User avatar
Vitalii
Staff Member
Staff Member
Posts: 95
Joined: Fri Jun 09, 2006 12:33 pm
Location: USA

Re: molecular formula of the compound

Post by Vitalii »

yon wrote:here are the problems---

A compound analyzes to be 37.5% C, 12.5% H, and 50.0% O. The molecular mass of the compound is 93.0. What is the molecular formula of the compound? (Type your answer using the format CH4 for CH4. Keep the elements in the order given.)

--------------------------------------------------------------------------------

40.
the composition of nicotine is 74.0% C, 8.7% H, and 17.3% N. Its molecular mass is 162. What is its molecular formula? (Type your answer using the format CH4 for CH4. Keep the elements in the order given.)

plz show how u did the problems
Just multiply molar mass by percent composition and divide by atomic weight of th atom.

For the second example:
C 162 * 74.0/100 /12 = 10
H 162 * 8.7/100/1.008 = 14
N 162 * 17.3/100/14 = 2
Thus the formula is C10H14N2
Post Reply