Need help on two questions (electron configuration and stoichiometry

[roxy6]

A compound is analyzed and it contains H,N,O and C. The original sample is 1.3957 grams. The sample is burned in excess oxygen to form 2.24 grams of CO2. 0.04 grams H is evaluated in the original sample.

a. What are the grams of oxygen in the original sample?
b. The original compound contains 28.84% N, how many grams of N are there?
c. How many grams of C are in the original compound?
d. What is the empirical formula for this compound?

How would you do this step by step and what are the solutions?

I was only able to get part B which was .0403 grams i believe?

I have a midterm tomorrow and need urgent help.

Thank you

 

[gravenewworld]

A compound is analyzed and it contains H,N,O and C. The original sample is 1.3957 grams. The sample is burned in excess oxygen to form 2.24 grams of CO2. 0.04 grams H is evaluated in the original sample.

a. What are the grams of oxygen in the original sample?
b. The original compound contains 28.84% N, how many grams of N are there?
c. How many grams of C are in the original compound?
d. What is the empirical formula for this compound?

How would you do this step by step and what are the solutions?

I was only able to get part B which was .0403 grams i believe?

I have a midterm tomorrow and need urgent help.

Thank you

b- correct
c- how many moles of C are in 2.24 grams of CO2? What is that in grams?
a- Subtract b, c, and 0.04 grams H from the original sample weight. That gives you the amount of oxygen in the original compound.
d-after you find everything in grams you can covert it to moles. Find the ratios between each government.