Chapter 3 Test

Question 1

What is the coefficient in a balanced reaction equation for hydrochloric acid when calcium hydroxide reacts with hydrochloric acid to produce calcium chloride and water according to the reaction:
Ca(OH)2 + HCl → CaCl2 + H2O

Answer 1

2

Question 2

What are the conversion factors that would be used to determine the number of atoms of oxygen in 0.23 moles of silver nitrate (AgNO3 )?

Answer 2

3 atoms oxygen/1 formula unit AgNO3

6.022*10^23 atoms/1 mole

Question 3

Which is the best balanced equation for the following reaction?

Al2(SO4 )3 + Ba(NO3 )2 → BaSO4 + Al(NO3 )3

Answer 3

Al2(SO4 )3 + 3Ba(NO3 )2 → 3BaSO4 + 2Al(NO3 )3

Question 4

What coefficient should be in front of nitrogen dioxide, NO2, in the balanced equation for the following reaction?

N2O5 → NO2 + O2

Answer 4

4

Question 5

Which of the following equations is balanced for the reaction?
HF + SiO2 → SiF4 + H2O

Answer 5

4HF + SiO2 → SiF4 + 2H2O

Question 6

Which equation is balanced for the following reaction?

Al + H2O → Al2O3 + H2

Answer 6

2Al + 3H2O → Al2O3 + 3H2

Question 7

How many atoms are found in 8.3 moles of potassium?

Answer 7

5.0 × 10^24 atoms of potassium

Question 8

How many atoms of uranium are there in 3.02 moles of this substance?

Answer 8

1.82 × 10^24 atoms

Question 9

What is the relationship between acetic acid (C2H4O2 ) and glyceraldehyde (C3H6O3 )?

Answer 9

Both molecules have the same empirical formula

Question 10

An unknown pesticide is made up of 18.28% carbon, 0.77% hydrogen, and 80.95% chlorine. What is the empirical formula of the pesticide?

Answer 10

C2HCl3

Question 11

Which of the following expressions correctly sets up the calculation needed to determine the number of grams of KClO3 produced during the reaction of 0.150 moles of Cl2 in excess potassium hydroxide according to the following reaction?

3Cl2 + 6KOH → 5KCl + KClO3 + 3H2 O

Answer 11

0.150 mol Cl2 * 1mol KCLO3/3mol Cl2 * 122.548g KCLO3/1mol KCLO3

Question 12

Usng the following balanced chemical equation, determine the limiting reactant in the reaction between 3.0 grams of titanium and 8.0 grams of chlorine gas?

Ti(s) + 2Cl2(g) → TiCl4(s)

Answer 12

Cl2

Question 13

What is the limiting reactant in the following reaction, if 75.0 g of zinc oxide and 50.0 g of carbon monoxide are used?

ZnO(s) + CO(g) → Zn(s) + CO2(g)

Answer 13

ZnO

Question 14

A chemist is producing copper(II) chloride using the following reaction:
Cu(s) + Cl2(g) = CuCl2(s)
In one reaction, the chemist uses 15.0 g of copper metal and 10.0 g of chlorine gas as reactants. When the reaction reaches completion, 16.0 g of copper(II) chloride has been produced. What was the percent yield of the reaction?

Answer 14

84.4%

Question 15

If you mix 12 moles of H2 and 7 moles of O2 to form H2O, which is the limiting reagent and why?

Answer 15

H2, because all 12 moles are used up.

Question 16

What is the molar mass of the element calcium?

Answer 16

40.078

Question 17

In the portion of the periodic table shown, what does the number 12.0107 represent?

Answer 17

molar mass

Question 18

What is the empirical formula of a substance with a molecular mass of 100.20 which is found to contain 83.91% carbon and 16.09% hydrogen?

Answer 18

C7H16

Question 19

Which of the following compounds has the greatest mass percent of carbon?

Answer 19

ethanol, C2H5OH

Question 20

Clonazepam, C15H10N3ClO3 is a drug in the benzodiazepine class of pharmaceuticals. It is a highly potent anticonvulsant, amnesiac and anxiolytic. Calculate the percent by mass of each of the elements in clonazepam. Carbon makes up the largest percent by mass to this compound. Which element contributes the second largest percent by mass to this compound?

Answer 20

oxygen

Question 21

How many atoms would be found in 1.2 grams of copper?

Answer 21

1.1 × 10^22 copper atoms

Question 22

What is the mass of the oxygen in 2.0 moles of silver nitrate (AgNO3)?

Answer 22

96 grams

Question 23

How many grams of hydrazine, N2H4, are produced from the reaction of 5.0 moles of N2 with an excess of H2, as shown in the following equation:

2H2(g) + N2(g) → N2H4(g)

Answer 23

160 g

Question 24

Using the following balanced chemical equation, calculate the number of grams of aluminum bromide (AlBr3 ) formed during the reaction of 1.50 moles of HBr in the presence of excess aluminum hydroxide. 3HBr(aq) + AL(OH)3(aq) -> ALBr3(aq) + 3H2O(l)

Answer 24

133. grams

Question 25

What is the molar mass of glucose, C6H12O6?

Answer 25

180.155 grams / mole