Unit Test — Unit test Answers

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This formula equation is unbalanced.BaCl2(aq) + Na2CO3(aq) BaCO3(s) + NaCl(aq) Which coefficient should be placed in front of NaCl to balance this equation?

Question illustration
A
1
B
2
C
3
D
4
2
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The balanced equation shows how sodium chloride reacts with silver nitrate to form sodium nitrate and silver chloride.NaCl + AgNO3 NaNO3 + AgCl If 4.00 g of NaCl react with 10.00 g of AgNO3, what is the excess reactant?

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A
AgCl
B
NaCl
C
AgNO3
D
NaNO3
3

An unbalanced chemical equation for the reaction of boron fluoride with lithium sulfite is shown below.BF3 + Li2SO3 B2(SO3)3 + LiFWhat is the coefficient of lithium fluoride in the balanced chemical reaction?

Question illustration
A
1
B
3
C
4
D
6
4

Which word equation shows lithium oxide being formed from the reaction between oxygen and lithium?

A
oxygen + lithium oxide lithium
Option A
B
lithium + oxygen lithium oxide
Option B
C
oxygen + lithium lithium + oxide
Option C
D
lithium oxide lithium + oxygen
Option D
5

If a substance reacts with oxygen, the chemical reaction is most likely a

A
combustion reaction.
B
decomposition reaction.
C
single replacement reaction.
D
double replacement reaction.
6

Which process is a chemical change?

A
breaking of glass
B
formation of frost
C
magnetization of an iron nail
D
loss of atmospheric ozone
7

Consider the equation below.Zn + H2SO4 ZnSO4 + H2The mole ratio of zinc to zinc sulfate is

Question illustration
A
1:1.
B
1:2.
C
2:1.
D
3:1.
8

Which statement best explains the purpose of using a mole in the measurement of matter?

A
It is commonly used as another unit of mass.
B
It allows chemists to deal with a large number of atoms.
C
It is used only for studying the properties of gases.
D
It explains that substances with the same moles have the same mass.
9

The chemical equation below shows the formation of aluminum oxide (Al2O3) from aluminum (Al) and oxygen (O2).4Al + 3O2 2Al2O3The molar mass of O2 is 32.0 g/mol. What mass, in grams, of O2 must react to form 3.80 mol of Al2O3?

Question illustration
A
60.8 grams
B
81.1 grams
C
122 grams
D
182 grams
10

What is the relationship between a mole and Avogadro’s number?

A
A mole is the mass of Avogadro’s number of particles of a substance.
B
A mole is the amount of a compound that has Avogadro’s number of carbon-12 atoms in it.
C
A mole contains Avogadro’s number of particles of a substance.
D
A mole is the amount of any substance that has the same mass as Avogadro’s number of carbon-12 atoms.
11

Sodium combines with water to produce sodium hydroxide and hydrogen gas. Which word equation represents this violent reaction?

A
sodium hydroxide + water sodium + hydrogen
Option A
B
sodium + water sodium hydroxide + hydrogen
Option B
C
sodium + hydrogen sodium hydroxide + water
Option C
D
sodium + sodium hydroxide water + hydrogen
Option D
12

The molar mass of water (H2O) is 18.0 g/mol. A sample of water has a mass of 18.0 g. How many moles of water are contained in this sample?

A
1.00 mole
B
18.0 moles
C
36.0 moles
D
324 moles
13

In a chemical reaction, substance R reacts with compound XY to produce 47.0 g of compound RX. If the theoretical yield of RX is 56.0 g, what is its percent yield?Use .

Question illustration
A
9.00%
B
16.1%
C
83.9%
D
119%
14

Consider the reaction below.2Al2O3 4Al + 3O2How many moles of oxygen are produced if 11.0 mol of Al are produced?

Question illustration
A
8.25 mol
B
11.0 mol
C
14.7 mol
D
16.5 mol
15

Consider the equation for the formation of water.2H2 + O2 2H2OWhat is the theoretical yield of H2O if 130 g of H2O is produced from 18 g of H2 and an excess of O2?

Question illustration
A
18 g
B
81 g
C
130 g
D
160 g

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