CHEM 1100
Answers for Practice Test 2

Note: Correct answers are given in red


1. When 22.0 g NaCl and 21.0 g H₂SO₄ are mixed and react according to the equation below, which is the limiting reagent?

2 NaCl + H₂SO₄ ---> Na₂SO₄ + 2 HCl

a. NaCl
b. H₂SO₄
c. Na₂SO₄
d. HCl
e. No limiting reagent


2. What is the maximum number of grams of ammonia, NH₃, that can be obtained from 10.0 g of H₂ reacting with 80.0 g of N₂?

N₂ + 3 H₂ ---> 2 NH₃

a. 28.4 g
b. 48.6 g
c. 56.7 g
d. 90.0 g
e. 97.1 g


3. What is the theoretical yield of aluminum that can be produced by the reaction of 60.0 g of aluminum oxide with 30.0 g of carbon acording tothe following equation?

Al₂O₃ + 3 C ---> 2 Al + 3 CO a. 30.0 g
b. 7.9 g
c. 101.2 g
d. 45.0 g
e. 31.8 g


4. What is the mass in grams of one arsenic atom?

a. 5.48 x 10^-23
b. 33.0 g
c. 74.9 g
d. 1.24 x 10^-22 g
e. 8.04 x 10²¹ g


5. The mass of 1.63 x 10²¹ silicon atoms is:

a. 2.71 x 10^-23 g
b. 4.58 x 10²² g
c. 28.08 g
d. 1.04 x 10⁴ g
e. 7.60 x 10^-2 g


6. Calculate the number of moles in 12.0 g of phosphorus

a. 0.387 mol
b. 0.80 mol
c. 2.58 mol
d. 12.0 mol
e. 6.02 x 10²³ mol


7. Which is the molar mass of acetaminophen, C₈H₉NO₂?

a. 151 g
b. 76 g
c. 43 g
d. 163 g
e. 125 g


8. How many grams of sulfur are contained in 6.00 g of Fe₂(SO₄)₃ ?

a. 2.40 g
b. 0.48 g
c. 6.00 g
d. 0.92 g
e. 1.44 g


9. What is the coefficent of H₂SO₄ when the following equation is properly balanced with the smallest set of whole numbers?

___ Ca₃(PO₄)₂ + ___ H₂SO₄ ---> ___ CaSO₄ + ___ H₃PO₄
a. 3
b. 8
c. 10
d.11
e. none of the above


10. What is the coefficent of O₂ when the following equation is properly balanced with the smallest set of whole numbers?

___ CH₃OH + ___ O₂ ---> ___CO₂ + ___ H₂O

a. 1
b. 2
c. 3
d.7
e.none of the above


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