Caffeine a stimulant found in coffee has the mass composition of C, 49.48%, H, 5.19%, N, 28.85%, O 16.48%. The molar mass of caffeine is 194.19g/mol. Find the molecular formula for caffeine.

  1. 👍 0
  2. 👎 0
  3. 👁 207
  1. Take 100 g sample which gives you
    48.48g C
    5.19 g H
    28.85g N
    16.48g O.
    Now convert grams to moles with moles = grams/molar mass
    Then find the ratio of the elements to the smallest one with it being no less than 1.00. The easy way to do that is to divide the smallest number by itself (thereby assuring a 1.00 for that element), then divide all of the other numbers by the same small number, round to whole numbers, and that should be the empirical formula. Check the mass of the empirical formula to see if the molar mass is 1x, 2x, 3x, etc of the empirical mass. I worked it and found the empirical formula of C4H5N2O.

    1. 👍 0
    2. 👎 0
  2. I got that as well but then I took the molar mass and divided by the empirical formula and got C8H10N4O2

    1. 👍 0
    2. 👎 0
    posted by Monique
  3. C8H10N4O2 is the molecular formula.

    1. 👍 0
    2. 👎 0

Respond to this Question

First Name

Your Response

Similar Questions

  1. Algebra

    Hot Java Coffee Company adverties their decaffeinated coffee as 97% caffeine free as compared to their regular caffeinated coffee. If a cup of coffee is 8 ounces, how many ounces of decaffeinated coffee would you have to drink to

    asked by Bob on November 2, 2010
  2. Biochemistry

    Hi, In this task for our school, we were requested to investigate a method for testing the amount of caffeine content in coffee. There are 3 main questions as fellows 1. What would be a good method to measure the amount of

    asked by Dave on February 8, 2010
  3. Chemistry

    Caffeine C8H10N4O2, is a stimulant found in a tea and coffee. A sample of the substance was dissolved in 45.0g of choloroform CHCl3 to give a 0.0946m solution. How many grams of caffine were in the sample. m = molality

    asked by Lauren on February 6, 2008
  4. biology

    Caffeine is the most widely used stimulant in the world today. This naturally produced molecule is found in popular beverages from coffee to black tea to Coca Cola. Although humans use caffeine to ward off drowsiness, the caffeine

    asked by selly on March 13, 2013
  5. Stats

    Instructions for the Experiment / Data Collection regarding questions 1-4: Collect data regarding the caffeine content in a 16oz cup of coffee. Collect the amount of caffeine in 20 different brands of coffee. 1.Calculate the

    asked by Nisa (Please Help me) on April 19, 2015
  6. statistics

    The caffeine content of a cup of home-brewed coffee is a normally distributed random variable with a mean of 115 mg with a standard deviation of 20 mg. (a) What is the probability that a randomly chosen cup of home-brewed coffee

    asked by Alejandra on October 24, 2010
  7. Algebra

    A cup of coffee contains about 100mg caffeine. The exponential function A(t)=100(0.84)^t is used to calculate the amount of caffeine in a body t hours after the coffee was consumed. Find the amount of caffeine in the body after 4

    asked by ##000000 on September 17, 2012
  8. university chemistry

    this is for a chemistry laboratory experiment called "how much caffeine is there in instant coffee" What should be the pH of the aqueous layer to extract caffeine? There are three aqueous solutions that you may choose from. A. pH

    asked by angela on March 12, 2013
  9. word problem urgent

    The half-life caffeine in the human body is typically about 6 hours. If john drinks a large cafe mocha with an extra shot of expresso from a coffee shop at 8am (255mg caffeine), and then starts to feel drowsy around 4pm and drinks

    asked by seby on August 10, 2015
  10. Math

    When you drink a cup of coffee or a glass of cola, or when you eat a chocolate bar, the percent, P, of caffeine remaining in your bloodstream is related to the elapsed time, t, in hours, by t=5(logP/log0.5). a) how long will it

    asked by Jus on May 21, 2009

More Similar Questions