# chemistry

last one, i PROMISE

A compound containing only C, H, O and Cr was subjected to combustion analysis. A sample of 10.88 mg produced 22.43 mg of CO2 and 4.59 mg of H2O. The chromium in the sample was precipitated as 14.09 mg of Ag2CrO4. Determine the empirical formula of the compound and match each element with its correct subscript from the drop box.

1. 👍
2. 👎
3. 👁
1. %CO2 = (23.43/10.88)*100.
%H2O = (4.59/10.88)*100.
For Cr, convert 14.09 mg Ag2CrO4 to g, then to mols Ag2CrO4, then to mols Cr, then to %Cr using the same format as above.
%O = 100% - %CO2 - %H2O - %Cr.
Now take a 100 g sample which will give you xx g CO2, yy g H2O, zz O and ww g Cr.
Convert g to mols C, H, O, and Cr.
Then find the ratio of each. The easy way to do this is to divide the smallest number by itself, then divide all the other mols by that number. Post your work if you need more help.

This should get you started.
Determine

1. 👍
2. 👎
2. I hope you didn't spend much time on this for I am way off base, including some typos. You need to look up the actual molar masses. I have estimated some of them. I just don't know what I was thinking. (I wasn't thinking.)

%C =[22.42 x (1 mol C/1 mol CO2)/10.88]*100 = [22.42 x (12/44)/10.88]*100 = xx
%H = [4.59 x (2 mol H/1 mol H2O/10.88]*100 = [4.59 x (2/18)/10.88] = yy
%Cr = [14.08 x (1 mol Cr/1 mol Ag2CrO4)/10.88]*100 = [14.08 x (52/331.7)/10.88]*100 = zz
%O = %C - %H - %Cr = ww
Now take a 100 g sample which will give you xx g C, yy g H, zz g Cr and ww g O
Then find the ratio of each. The easy way to do this is to divide the smallest number by itself, then divide all the other mols by that number. Post your work if you need more help.

1. 👍
2. 👎
3. After you take the 100 g sample, you want to take the grams of each and convert to mols, then find the ratio of the mols.
So,
xx/12= mols C
yy/1 = mols H
zz/52 = mols Cr
ww/16 = mols O

1. 👍
2. 👎

## Similar Questions

1. ### English

Identify the structure used in each of the sentences below. 1. The hamburger came from Hamburg, Germany, and the hot dog came from Frankfurt. simple compound complex compound-complex 2. The idea of placing meat on a bun, however,

2. ### English

Choose the term that describes the type of sentence shown. If you are in line early, you'll be sure to get the best tickets. A.) compound-complex B.) complex C.) compound D.) simple I think it is C? John was late to dinner and I

3. ### English

My name, Cynthia, is from a Greek word for moon. a. simple sentence ** b. compound sentence c. complex sentence d. compound-complex sentence I was not surprised when I learned that. a. simple sentence *** b. compound sentence c.

4. ### Language arts check answers

If you fail to plan, you plan to fail. simple complex compound

1. ### chemistry

3-pentanol is heated with sulphuric acid (H2SO4) to become compound M. Compound M is reacted with Br2/ H2O to form Compound N. Outline the reaction step and name the compound M and N

2. ### English

The basket (that she is holding) is made from palm fronds. independent clause adjective clause adverb clause noun clause If you fail to plan, you plan to fail. simple complex compound compound-complex John was late to dinner and I

3. ### Chemistry

A compound containing only carbon, hydrogen and oxygen is subjected to elemental analysis. Upon complete combustion, a .1804g sample of the compound produced .3051g of CO2 and .1249g of H2O. What is the empirical formula of the

4. ### Chemistry

A compound contains only carbon, hydrogen, nitrogen, and oxygen. Combustion of 0.157 of the compound produced 0.213g CO2 and 0.0310 g H20. In another experiment, it is found that 0.103g of the compound produces 0.0230 g NH3. What

1. ### Chemistry

A compound contains 'N' and 'O' atom. The ratio of mass percentage of 'N' and 'O' is 7:16. If the vapour density of compound is 46, then find the no of 'O' atoms present per molecule of the compound.

2. ### English

Would the sentence below be: SIMPLE, COMPLEX, COMPOUND, or COMPOUND COMPLEX? The students prepared for the exam, and the instructors administered it on Thursday. Would it be a compound sentence? You are right. These are two

3. ### stoichiometry

A confiscated white substance, suspected of being cocaine, was purified by a forensic chemist and subjected to elemental analysis. Combustion of a 50.86-mg sample yielded 150.0 mg CO2 and 46.05 mg H2O. Analysis for nitrogen showed

4. ### Chem

Compound B is burned in a bomb calorimeter that contains 1.50 liters of water. When I burned 50.0 grams of compound B in the calorimeter, the temperature rise of the water in the calorimeter was 35.0 degrees C. If the heat of