Download Practice problems for chapter 1, 2 and 3 1) A small amount of salt

Practice problems for chapter 1, 2 and 3
1) A small amount of salt dissolved in water is an example of a __________.
2) Which one of the following is a pure substance?
A) concrete
B) wood
C) salt water
D) elemental copper
E) milk
3) For which of the following can the composition vary?
A) pure substance
B) element
C) both homogeneous and heterogeneous mixtures
D) homogeneous mixture
E) heterogeneous mixture
4) An element cannot __________.
5) Homogeneous mixtures are also known as __________.
6) In the following list, only __________ is not an example of a chemical reaction.
A) dissolution of a penny in nitric acid
B) the condensation of water vapor
C) a burning candle
D) the formation of polyethylene from ethylene
E) the rusting of iron
7) Of the following, only __________ is a chemical reaction.
A) melting of lead
B) dissolving sugar in water
C) tarnishing of silver
D) crushing of stone
E) dropping a penny into a glass of water
8) Which of the following are chemical processes?
1. rusting of a nail
2. freezing of water
3. decomposition of water into hydrogen and oxygen gases
4. compression of oxygen gas
A) 2, 3, 4
B) 1, 3, 4
C) 1, 3
D) 1, 2
E) 1, 4
9) In the following list, only __________ is not an example of a chemical reaction.
1
Copyright © 2012 Pearson Education, Inc.
A) burning a plastic water bottle
B) the production of hydrogen gas from water
C) the tarnishing of a copper penny
D) chopping a log into sawdust
E) charging a cellular phone
10) Of the following, __________ is the smallest mass.
A) 25 kg
B) 2.5 × 10-2 mg
C) 2.5 × 1015 pg
D) 2.5 × 109 fg
E) 2.5 × 1010 ng
11) Of the following, __________ is the largest mass.
A) 25 kg
B) 2.5 × 10-2 mg
C) 2.5 × 1015 pg
D) 2.5 × 109 fg
E) 2.5 × 1010 ng
12) Which one of the following is the highest temperature?
A) 38 °C
B) 96 °F
C) 302 K
D) none of the above
E) the freezing point of water
13) Which of the following is (are) the lowest temperature?
A) The freezing point of water
B) 5 °C
C) 30 °F
D) 280 K
E) A and D
14) Express the temperature, 422.35 K, in degrees Celsius.
15) Which of the following liquids has the greatest density?
A) 13
with a mass of 23 g
3
B) 3.5 cm with a mass of 10 g
C) 0.022 cm3 with a mass of 0.10 g
D) 54 cm3 with a mass of 45 g
E) 210 cm3 with a mass of 12 g
2
Copyright © 2012 Pearson Education, Inc.
16) Osmium has a density of 22.6 g/cm3. What volume (in cm3) would be occupied by a 21.8 g sample
of osmium?
17) Accuracy refers to __________.
18) Which of the following has the same number of significant figures as the number 1.00310?
A) 1 × 106
B) 199.791
C) 8.66
D) 5.119
E) 100
19) A wooden object has a mass of 10.782 g and occupies a volume of 13.72 mL. What is the density of
the object determined to an appropriate number of significant figures?
20) The number with the most significant zeros is __________.
A) 0.00002510
B) 0.02500001
C) 250000001
D) 2.501 × 10-7
E) 2.5100000
21) How many significant figures are in the number 0.0034050?
22) How many significant figures should be retained in the result of the following calculation?
12.00000 × 0.9893 + 13.00335 × 0.0107
23) In which one of the following numbers are all of the zeros significant?
A) 100.090090
B) 0.143290
C) 0.05843
D) 0.1000
E) 00.0030020
24) In which one of the following numbers are none of the zeros significant?
A) 100.0
B) 1065
C) 0.0100
D) 1.003450
E) 0.00001
25) Round the number 0.007222 to three significant figures.
26) Round the number 3456.5 to two significant figures.
27) Round the number 0.08535 to two significant figures.
3
Copyright © 2012 Pearson Education, Inc.
28) The SI unit for mass is __________.
29) __________ is the abbreviation for the prefix mega-.
30) Milli is the abbreviation for the prefix ________.
31) A common English set of units for expressing velocity is miles/hour. The SI unit for velocity is
__________.
32) The density of a gold nugget is 19.3 g/cm3. If the volume of the gold nugget is 0.00369 L, the mass
of the nugget is __________.
33) The SI unit of temperature is __________.
34) A temperature of __________ K is the same as 63°F.
35) 1 nanometer = __________ picometers
36) The correct answer (reported to the proper number of significant figures) to the following is
6.3 × 3.25 = _____
37) The correct answer (reported to the proper number of significant figures) to the following is
__________.
(2.05631)(6.9391136) / 12.59326 = _____
38) The correct answer (reported to the proper number of significant figures) to the following is
__________.
12.75 x 1.3621 = _____
39) The correct answer (reported to the proper number of significant figures) to the following is
__________.
(12.67 + 19.2)(3.99) / (1.36 + 11.366) = _____
40)
= __________
Chemistry: The Central Science, 12e (Brown et al.)
Chapter 2 Atoms, Molecules, and Ions
1) There are __________ electrons, __________ protons, and __________ neutrons in an atom of
4
Copyright © 2012 Pearson Education, Inc.
132 Xe .
54
A) 132, 132, 54
B) 54, 54, 132
C) 78, 78, 54
D) 54, 54, 78
E) 78, 78, 132
2) An atom of the most common isotope of gold, 197Au, has __________ protons, __________
neutrons, and __________ electrons.
A) 197, 79, 118
B) 118, 79, 39
C) 79, 197, 197
D) 79, 118, 118
E) 79, 118, 79
63 Cu ?
3) Which combination of protons, neutrons, and electrons is correct for the isotope of copper, 29
A) 29 p+, 34 n°, 29 eB) 29 p+, 29 n°, 63 eC) 63 p+, 29 n°, 63 eD) 34 p+, 29 n°, 34 eE) 34 p+, 34 n°, 29 e4) Which isotope has 45 neutrons?
A) 80
36 Kr
B) 80
35 Br
78 Se
C) 34
34 Cl
D) 17
E) 103
45 Rh
5) Which pair of atoms constitutes a pair of isotopes of the same element?
14 X
A) 146 X
7
12 X
B) 146 X
6
17 X
C) 179 X
8
19 X
D) 19
10 X
9
21 X
E) 20
11
10 X
6) Which isotope has 36 electrons in an atom?
5
Copyright © 2012 Pearson Education, Inc.
A) 80
36 Kr
B) 80
35 Br
78 Se
C) 34
34 Cl
D) 17
E) 36
80 Hg
7) Isotopes are atoms that have the same number of __________ but differing number of __________.
A) protons, electrons
B) neutrons, protons
C) protons, neutrons
D) electrons, protons
E) neutrons, electrons
8) Different isotopes of a particular element contain the same number of __________.
A) protons
B) neutrons
C) protons and neutrons
D) protons, neutrons, and electrons
E) subatomic particles
9) Different isotopes of a particular element contain different numbers of __________.
A) protons
B) neutrons
C) protons and neutrons
D) protons, neutrons, and electrons
E) None of the above is correct.
10) In the symbol below, X = __________.
13 X
6
A) N
B) C
C) Al
D) K
E) not enough information to determine
11) In the symbol below, x is __________.
xC
6
A) the number of neutrons
B) the atomic number
C) the mass number
D) the isotope number
E) the elemental symbol
6
Copyright © 2012 Pearson Education, Inc.
12) The element X has three naturally occurring isotopes. The masses (amu) and % abundances of the
isotopes are given in the table below. The average atomic mass of the element is __________ amu.
A) 219.7
B) 220.4
C) 220.42
D) 218.5
E) 221.0
13) Element X has three naturally occurring isotopes. The masses (amu) and % abundances of the
isotopes are given in the table below. The average atomic mass of the element is __________ amu.
A) 41.54
B) 39.68
C) 39.07
D) 38.64
E) 33.33
14) The average atomic weight of copper, which has two naturally occurring isotopes, is 63.5. One of
the isotopes has an atomic weight of 62.9 amu and constitutes 69.1% of the copper isotopes. The other
isotope has an abundance of 30.9%. The atomic weight (amu) of the second isotope is __________ amu.
A) 63.2
B) 63.8
C) 64.1
D) 64.8
E) 28.1
15) An unknown element is found to have three naturally occurring isotopes with atomic masses of
35.9675 (0.337%), 37.9627 (0.063%), and 39.9624 (99.600%). Which of the following is the unknown
element?
A) Ar
B) K
C) Cl
D) Ca
E) None of the above could be the unknown element
7
Copyright © 2012 Pearson Education, Inc.
16) Which pair of elements would you expect to exhibit the greatest similarity in their physical and
chemical properties?
A) H, Li
B) Cs, Ba
C) Ca, Sr
D) Ga, Ge
E) C, O
17) Which pair of elements would you expect to exhibit the greatest similarity in their physical and
chemical properties?
A) O, S
B) C, N
C) K, Ca
D) H, He
E) Si, P
18) Which one of the following does not occur as diatomic molecules in elemental form?
A) oxygen
B) nitrogen
C) sulfur
D) hydrogen
E) bromine
19) Which one of the following molecular formulas is also an empirical formula?
A) C6H6O2
B) C2H6SO
C) H2O2
D) H2P4O6
E) C6H6
20) Of the choices below, which one is not an ionic compound?
A) PCl5
B) MoCl6
C) RbCl
D) PbCI2
E) NaCl
21) Which one of the following is most likely to lose electrons when forming an ion?
A) F
B) P
C) Rh
D) S
E) N
22) Which species is an isotope of 39Cl?
A) 40Ar+
8
Copyright © 2012 Pearson Education, Inc.
B) 34S2C) 36ClD) 80Br
E) 39Ar
23) There are __________ protons, __________ neutrons, and __________ electrons in 131I-.
A) 131, 53, and 54
B) 131, 53, and 52
C) 53, 78, and 54
D) 53, 131, and 52
E) 78, 53, and 72
24) Which of the following compounds would you expect to be ionic?
A) SF6
B) H2O
C) H2O2
D) NH3
E) CaO
25) Which pair of elements is most apt to form a molecular compound with each other?
A) aluminum, oxygen
B) magnesium, iodine
C) sulfur, fluorine
D) potassium, lithium
E) barium, bromine
26) Which species below is the nitride ion?
A) Na+
B) NO3C) NO2D) NH4+
E) N327) Which species below is the sulfite ion?
A) SO2-2
B) S O3-2
C) S2D) SO4-2
E) HS28) The charge on the copper ion in the salt CuO is __________.
A) +1
B) +2
C) +3
9
Copyright © 2012 Pearson Education, Inc.
D) -1
E) -2
29) The charge on the iron ion in the salt Fe2O3 is __________.
A) +1
B) +2
C) +3
D) -5
E) -6
30) Horizontal rows of the periodic table are known as __________.
A) periods
B) groups
C) metalloids
D) metals
E) nonmetals
31) Elements in Group 7A are known as the __________.
A) chalcogens
B) alkali metals
C) alkaline earth metals
D) halogens
E) noble gases
32) When a metal and a nonmetal react, the __________ tends to lose electrons and the __________
tends to gain electrons.
A) metal, metal
B) nonmetal, nonmetal
C) metal, nonmetal
D) nonmetal, metal
E) None of the above, these elements share electrons.
33) The charge on the manganese in the salt MnF3 is __________.
A) 1+
B) 1C) 2+
D) 2E) 3+
34) Potassium forms an ion with a charge of __________.
A) 2+
B) 1C) 1+
D) 2E) 0
35) Aluminum forms an ion with a charge of __________.
A) 2+
10
Copyright © 2012 Pearson Education, Inc.
B) 3C) 1+
D) 3+
E) 137) Fluorine forms an ion with a charge of __________.
A) 1B) 1+
C) 2+
D) 3+
E) 338) The ions Ca2+and PO43- form a salt with the formula __________.
A) CaPO4
B) Ca2 (PO4)3
C) Ca2PO4
D) Ca(PO4)2
E) Ca3 (PO4)2
39) How many electrons does the Al3+ ion possess?
A) 16
B) 10
C) 6
D) 0
E) 13
40) How many protons does the Br- ion possess?
A) 34
B) 36
C) 6
D) 8
E) 35
Chapter 3
1) Balance the following equation
C8H18 + O2 → CO2 + H2O
2) Of the reactions below, which one is not a combination reaction?
A) C + O2 → CO2
B) 2Mg + O2 → 2MgO
C) 2N2 + 3H2 → 2NH3
D) CaO + H2O → Ca(OH)2
11
Copyright © 2012 Pearson Education, Inc.
E) 2CH4 + 4O2 → 2CO2 + 4H2O
3) Of the reactions below, which one is a decomposition reaction?
A) NH4Cl → NH3 + HCl
B) 2Mg + O2 → 2MgO
C) 2N2 + 3 H2 → 2NH3
D) 2CH4 + 4O2 → 2CO2 + 4H2O
E) Cd(NO3)O2 + Na2S → CdS + 2NaNO3
4) Write the product of this combination reaction?
Al (s) + I2 (s) → __________
5) Which of the following are combustion reactions?
1) CH4 (g) + O2 (g) → CO2 (g) + H2O (l)
2) CaO (s) + CO2 (g) → CaCO3 (s)
3) PbCO3 (s) → PbO (s) + CO2 (g)
4) CH3OH (l) + O2 (g) → CO2 (g) + H2O (l)
6) The formula of nitrobenzene is C6H5N O2. The molecular weight of this compound is __________
amu.
7) The formula weight of potassium dichromate (K2Cr2O7) is __________ amu.
8) What is the mass % of carbon in dimethylsulfoxide (C2H6SO) rounded to three significant figures?
9) The mass % of Al in aluminum sulfate (Al2(SO4)3) is __________.
10) There are __________ atoms of oxygen are in 300 molecules of CH3CO2H.
A) 300
B) 600
C) 3.01 × 1024
D) 3.61 × 1026
E) 1.80 × 1026
11) How many molecules of CH4 are in 48.2 g of this compound?
12) A 30.5 gram sample of glucose (C6H12O6) contains __________ mol of glucose.
13) A sample of CH2F2 with a mass of 19 g contains __________ atoms of F.
14) A sample of CH4O with a mass of 32.0 g contains __________ molecules of CH4O.
15) Gaseous argon has a density of 1.40 g/L at standard conditions. How many argon atoms are in 1.00
12
Copyright © 2012 Pearson Education, Inc.
L of argon gas at standard conditions?
16) How many moles of pyridine (C5H5N) are contained in 3.13 g of pyridine?
17) How many grams of sodium carbonate contain 1.773 × 1017 carbon atoms?
18) Sulfur and oxygen react to produce sulfur trioxide. In a particular experiment, 7.9 grams of SO3 are
produced by the reaction of 5.0 grams of O2 with 6.0 grams of S. What is the % yield of SO3 in this
experiment?
S (s) + O2 (g) → SO3 (g) (not balanced)
19) Balance the following reaction
Al(NO3)3 + Na2S → Al2S3 + NaNO3
20) Balance the following reaction
HNO3 (aq) + CaCO3 (s) → Ca(NO3)2 (aq) + CO2 (g) + H2O (l)
21) Balance the following reaction
PbS (s) + O2 (g) → PbO (s) + SO2 (g)
13
Copyright © 2012 Pearson Education, Inc.