# chemistry

Ibuprofen, the active ingredient in Advil, is made up of carbon, hydrogen, and oxygen atoms. When a sample of ibuprofen, weighing 5.000 g, burns in oxygen, 13.86g of CO2 and 3.926 g of water are obtained. What is the simplest formula of ibuprofen?

I need to find out if I'm doing everything right here:

13.86g CO2 + 3.926g H2O

percent of C in CO2 is 12 / (12 + 2*16) = 30%
# of grams C = 13.86 * 30% = 4.16 g
moles C = 4.16 / 12 = 0.347

percent of H in H2O is 2/ (1(2) + 16) = 11.11%
# of grams H = 3.926 * 11.11% = 0.436 g
moles H = .436/1 = 0.436

# of grams O = 5.000 – (grams H + grams C) = 5.000 – 4.596 = 0.404 g
moles O = .404/16 = .0253

C = .347 / .0253 = 13.7
H = .436 / .0253 = 17.2
O = .0253 / .0253 = 1

C14H17O

I got this formula, but I looked up ibuprofen and saw that it has a C13H18O2 formula, so did I miss a doubling of oxygen moles somewhere, or maybe I'm just flat out wrong? please help!!

1. 👍 0
2. 👎 0
3. 👁 258
1. Two things. I don't get 30% for C in CO2 but more likle 27.27%. That will change mass C AND it will change mass O when you subtract to obtain grams O. Your H calculations look ok and the rest of the problem is ok. When I did it I obtained C13H18O2 and I looked it up on the web and found that is the formula. I don't know where you found the C14 number.
http://en.wikipedia.org/wiki/Ibuprofen
I hope this helps.

1. 👍 0
2. 👎 0
posted by DrBob222
2. yes that solved everything thanks!

1. 👍 0
2. 👎 0
posted by robert

## Similar Questions

1. ### Intro. Chemistry

Based on the law of definite composition, Dalton proposed that one atom of carbon combines with two atoms of oxygen to always produce CO2. Similarly,he proposed that two atoms of hydrogen combine with one atom of oxygen to give a

asked by Cliff on September 17, 2010
2. ### chemistry

Ibuprofen, the active ingredient in advil, is made up of carbon, hydrogen, and oxygen atoms. When a sample of ibuprofen, weighing 5.000 g, burns in oxygen, 13.86 g of CO2 and 3.926 g of water are obtained. What is the simplest

asked by Chris on October 17, 2006
3. ### Math

Glucose is a common type of sugar. One glucose molecule is made up of 24 atoms. 1/4 of the atoms are carbon, 1/2 are hydrogen atoms, and 1/4 are oxygen atoms. Part A: How many oxygen atoms are there in 50 atoms? Part B:Explain how

asked by Sherman on April 19, 2014

The active ingredient in the allergy medication Claritin contains carbon (C), hydrogen (H), chlorine (Cl), nitrogen (N), and oxygen (O). Its molecular formula is C22H23ClN2O2. The standard adult dosage utilizes 1.480 1019

asked by Mary on April 14, 2007
5. ### Science URGENT

Write down the number of hydrogen and oxygen atoms of the following H2O 3H2O 5H2O Write down the number of carbon, hydrogen and oxygen atoms: C6H12O6 2C6H12O6 10C6H12O6 Write down the number of molybdenum, oxygen and hydrogen

6. ### Chemistry

A compound containing 3 atoms of carbon and 8 atoms of hydrogen is combined in a reaction with oxygen molecules. The two end products of this equation are carbon dioxide and water. What element should you look at first in

asked by William on November 7, 2009

Which atoms are in all carbohydrates? A- carbon, phosphorus, oxygen B- carbon, nitrogen, oxygen C- carbon, hydrogen, oxygen D- carbon, hydrogen, nitrogen My choice is C. Which type of macromolecule is the sugar fructose? A-

asked by Alexandria on October 14, 2014
8. ### Science

the active ingredient in the alergy medication claritin contain carbon,hydrogen,chloride,nitrogen,and oxygen its molecules formula is C22H23ClN2O2.the standard adult gosage utizies 1.572*10^19 molecules of the spicies determine

asked by Kriatian ferrer on February 2, 2016
9. ### Math

In Science, one acetic acid molecule is made of 2 carbon atoms, 2 oxygen atoms, and 4 hydrogen atoms. The ratio of carbon atoms to all atoms in 2 molecules of acetic acid is _____ to _____

asked by Derek on February 3, 2019
10. ### CHM

Which of the following events are not examples of a chemical reaction? atoms of gold turning into atoms of iron conversion of methane, which contains carbon and hydrogen, and oxygen into carbon dioxide and water

asked by Jakey on January 27, 2013

More Similar Questions