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CP Chemistry Unit 2 Test (The Atom and the Mole)

Total questions: 29

Worksheet time: 7hrs 15mins

Name
Class
Date
1.

Indicate whether the statement is true or false. An element’s molar mass is equivalent to the atomic number of the element.

a)

True

b)

False

2.

Indicate whether the statement is true or false. In a neutral atom, the number of protons is equal to the number of neutrons.

a)

True

b)

False

3.

Indicate whether the statement is true or false. In the notation 107/47 Ag, 107 represents the atomic number and 47 represents the atomic mass of silver.

a)

True

b)

False

4.

Indicate whether the statement is true or false. Greek philosophers thought that matter was composed of four elements: air, earth, fire, and water.

a)

True

b)

False

5.

Indicate whether the statement is true or false. Isotopes are forms of an element that have the same number of protons but a different number of electrons.

a)

True

b)

False

6.

Find the formula for the compound that contains 72.40% iron and 27.60% oxygen.

a)

Fe3O4

b)

FeO2

c)

FeO

d)

Fe2O3

7.

How many electrons are in a neutral atom of sodium?

a)

11

b)

22

c)

12

d)

23

8.

How many neutrons are in an atom of chlorine?

a)

35

b)

18

c)

34

d)

17

9.

How many moles are present in 21.2 g hydrochloric acid, HCl?

a)

1.72 mol

b)

0.582 mol

c)

128 mol

d)

21.0 mol

10.

What is the molar mass of Ca(OH)2?

a)

57.008 g/mol

b)

73.089 g/mol

c)

73.088 g/mol

d)

74.092 g/mol

11.

Which scientist described an atom made of a solid positively charged substance with electrons dispersed throughout it, which he termed the "plum pudding model"?

a)

Thomson

b)

Rutherford

c)

Bohr

d)

Chadwick

12.

Which is the number of neutrons in 3580Br^{80}_{35}Br ?

a)

35

b)

115

c)

80

d)

45

13.

Which two are isotopes of one another?

a)

Atoms 2 & 3

b)

Atoms 1 & 3

c)

Atoms 1 & 2

d)

Atoms 1 & 4

14.

Which two have the same mass?

a)

Atoms 2 & 4

b)

Atoms 1 & 4

c)

Atoms 2 & 3

d)

Atoms 1 & 2

15.

Which is the formula for a compound that contains 64.75 g nitrogen and 185.25 g oxygen?

a)

NO

b)

N2O5

c)

NO2

d)

N2O

16.

How many individual atoms make up one unit of aluminum chloride, AlCl3?

a)

1

b)

4

c)

2

d)

3

17.

Which is the correct symbol for this atom?

a)

1120F^{20}_{11}F

b)

911F^{11}_{9}F

c)

1118F^{18}_{11}F

d)

920F^{20}_{9}F

18.

Copper (Cu) is a transition element used in the making of coins. Calculate the mass in grams of 0.0420 moles of copper.

a)

0.252 g

b)

2.67 g

c)

0.00697 g

d)

6.61 g

19.

Which is the correct molar mass for the compound FeSO₄?

a)

151.85 g/mol

b)

415.4 g/mol

c)

103.85 g/mol

d)

247.85 g/mol

20.

What is the mass of 2.25 moles of sulfuric acid (H₂SO₄)?

a)

112 g

b)

220 g

c)

98.0 g

d)

50.0 g

21.

Which scientist described a positively charged core (“nucleus”) in the middle of a lot of empty space?

a)

Chadwick

b)

Bohr

c)

Thomson

d)

Rutherford

22.

Calculate the number of atoms in 13.2 mol copper.

a)

7.95 × 10²³ atoms

b)

7.95 × 10²⁴ atoms

c)

7.95 × 10⁻²³ atoms

d)

2.19 × 10²³ atoms

23.

How many grams are in 1.946 moles of NaCl?

a)

0.033 g

b)

44.7 g

c)

30.1 g

d)

113.8 g

24.

How many atoms of copper (Cu) are in a pure copper coin weighing 12.0 g?

a)

0.0313 × 10²³ atoms

b)

1.10 × 10²³ atoms

c)

1.13 × 10²³ atoms

d)

0.187 × 10²³ atoms

25.

Find the empirical formula for the compound with this percent composition. Show your work. Element Percent Composition of Each Element Sodium 27.04 % Nitrogen 16.48% Oxygen 56.47%

a)

NaNO3

b)

Na2NO2

c)

NaNO2

d)

Na2O

26.

What is the average atomic mass (also called the WAM) of this element? Isotope Mass (amu) Percent Abundance Silver-105 105 48% Silver-108 108 43% Silver-109 109 9%

a)

106.5 amu

b)

106.92 amu

c)

107.5 amu

d)

108.5 amu

27.

Explain why this is not the correct dimensional analysis setup to determine the mass of 4.50 moles of KCl. (and it is not that 4.5 moles KCl should be put over '1'). 4.50 moles KCl × (39.10g / 1 mole) = 176g KCl

a)

The molar mass of KCl is incorrect.

b)

The units of moles do not cancel out correctly.

c)

The conversion factor is inverted.

d)

The calculation does not account for both K and Cl atoms.

28.

Write the isotopic chemical symbol for the isotope of cobalt with 37 neutrons.

a)

60Co

b)

59Co

c)

61Co

d)

58Co

29.

Calculate the number of protons, electrons, and neutrons in an atom of the element Pb with mass number 207 and atomic number 82.

a)

82 protons, 82 electrons, 125 neutrons

b)

82 protons, 82 electrons, 207 neutrons

c)

125 protons, 125 electrons, 82 neutrons

d)

207 protons, 207 electrons, 82 neutrons