#2-28: Percent Composition, Empirical Formula, and Molecular Formula:
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Last updated 11 months ago
10 questions
Note from the author:
Directions:
Round all percent composition answers to one after the decimal. If you use percent composition to find empirical formula, you may want to keep a few more decimal places.
Directions:
Round all percent composition answers to one after the decimal. If you use percent composition to find empirical formula, you may want to keep a few more decimal places.
Strychnine, a rat poison, has the following chemical formula:
C21H22N2O2
1
Question 1
1.
You are responsible for determining an unknown over-the-counter drug substance. In the lab, you ran a test to determine that the unknown drug sample contained the following percent composition:
60.00% Carbon
4.48% Hydrogen
35.53% Oxygen
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1
Caffeine contains the following percent composition:
49.5% Carbon
5.15% Hydrogen
28.9% Nitrogen
16.5% Oxygen
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Aspartame, an artificial sweetener, contains the following:
4.762 moles Carbon
6.160 moles Hydrogen
0.680 moles Nitrogen
1.699 moles Oxygen
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1
Nitroglycerine is a compound that is used in heart medications. It can also be used in explosives!
A 40.0-gram sample of Nitroglycerine contains:
6.348 grams Carbon
0.864 grams Hydrogen
7.260 grams Nitrogen
25.364 grams Oxygen
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1
1
Fill in the percent composition for each of the elements in this compound:
_______ % Carbon
_______ % Hydrogen
_______ % Nitrogen
_______ % Oxygen
Question 2
2.
What is the empirical formula?
Question 3
3.
Identify the drug sample:
Question 4
4.
What is the empirical formula?
Question 5
5.
If the molecular mass is approximately 195.0 g/mol.
What is the molecular formula?
Question 6
6.
Fill in the percent composition for each of the elements in this compound:
_______ % Carbon
_______ % Hydrogen
_______ % Nitrogen
_______ % Oxygen
Question 7
7.
Determine the empirical formula:
Question 8
8.
Fill in the percent composition for each of the elements in this compound:
_______ % Carbon
_______ % Hydrogen
_______ % Nitrogen
_______ % Oxygen
Question 9
9.
Determine the empirical formula:
Question 10
10.
If the molecular mass is approximately 227.0 g/mol.