Mg - University of California, Berkeley
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QUIZ #5, CHEM 001 (Chapter 7) Name: _________________________ Date: ________________________ You must show all work to receive any credit; and, where applicable, report all numerical answers to the proper number of significant figures. 1. What is the molar mass of CuSO 4 * 3H 2 O? [5 pts.] 2. How many grams of magnesium are contained in 212.07 g of MgSO 4 ? [5 pts.] 3. A compound whose molar mass is 92.02 g/mol was analyzed and found to contain 30.45 % N and 69.55 % O. What is the molecular formula of the compound? [15 pts.] ANSWER KEY 213.66 grams 1 mot Cusa , ' 3h20 42.83 grams Mg 30.45/14.01 = 2.17/2.17 = I ⇒ Noz empirical formula 69.55/16.00 = 4.35/2.17 = 2 ↳ molar mass 46.01g / Mol 92.02 glmol = 2 ⇒ Nz 04 molecular formula 46.01 glmol
Transcript of Mg - University of California, Berkeley
QUIZ #5, CHEM 001 (Chapter 7)
Name: _________________________ Date: ________________________
You must show all work to receive any credit; and, where applicable, report all numerical answers to the proper number of significant figures.
1. What is the molar mass of CuSO4 * 3H2O? [5 pts.]
2. How many grams of magnesium are contained in 212.07 g of MgSO4? [5 pts.]
3. A compound whose molar mass is 92.02 g/mol was analyzed and found to contain 30.45 % N and 69.55 % O. What is the molecular formula of the compound? [15 pts.]
ANSWER KEY
213.66grams
1 mot Cusa ,
' 3h20
42.83 grams Mg
30.45/14.01=
2.17/2.17= I
⇒ Noz empirical formula69.55/16.00=
4.35/2.17= 2
↳ molar mass 46.01g / Mol
92.02 glmol = 2 ⇒ Nz 04 molecular formula46.01 glmol
QUIZ #5, CHEM 001 (Chapter 7)
NAME: _________________________ Date: ________________________
You must show all work to receive any credit; and, where applicable, report all numerical answers to the proper number of significant figures.
1. What is the molar mass of Na2CO3 * 10H 2O? [5 pts.]
2. How many grams of oxygen are contained in 212.07 g of CuSO4? [5 pts.]
3. A compound whose molar mass is 152.08 g/mol was analyzed and found to contain 63.18 % C, 31.56% O, and 5.26 % H. What is the molecular formula of the compound? [15 pts.]
ANSWER KEY
286.19 glmol
85.04g
63.18/12.01 =
5.26/1.97
= 2.67 x 3 = 8
31.56/16.00 = 1.97/1.97 = I x 3= 3
5.26/1.01 =
5.21/1.97= 2.64 × 3 = 7.92 → 8
empirical formula C8Hq0z molar mass = 152.16glmol
molecular formula C8HqO3
QUIZ #5, CHEM 001 (Chapter 7)
Name: _________________________ Date: ________________________
You must show all work to receive any credit; and, where applicable, report all numerical answers to the proper number of significant figures.
1. What is the molar mass of CaCl 2 * 2H2O? [5 pts.]
2. How many grams of copper are contained in 212.07 g of CuSO4? [5 pts.]
3. A compound whose molar mass is 32.05 g/mole was analyzed and found to contain 87.4 % N and 12.6 % H. What is the molecular formula of the compound? [15 pts.]
ANSWER KEY
147.02 glmol
84.43g
87.4/14.01 =
6.24/6.24= I
empirical formula : NHZ
12.6/1.01 =
12.48/6.24= z
molar mass : 16.02 gland
molecular : Natty
QUIZ #5, CHEM 001 (Chapter 7)
Name: _________________________ Date: ________________________
You must show all work to receive any credit; and, where applicable, report all numerical answers to the proper number of significant figures.
1. What is the molar mass of CoCl 2 * 6H2O? [5 pts.]
2. How many grams of oxygen are contained in 212.07 g of MgSO4? [5 pts.]
3. A compound whose molar mass is 289.9 g/mol was analyzed and found to contain 49.67 % C, 48.92 % Cl, and 1.39 % H. What is the molecular formula of the compound? [15 pts.]
ANSWER KEY
237.95 glmol
112.76 grams
49.67/12.01
=
4.136/1.38=3
↳ CIH
48.92/35.45
= 1.38/1.38 = I
342.0ft1135.45)
-1111.01) =
72.49289.9/72.49= 4
1.39/1.01=
1.38/1.38= I
GzCl4H4
