General Chemistry Lec II
Problem 1
All of the following are clues that a chemical reaction has taken place except
The reactant is smaller.
a.A flame occurs.
b.A color change occurs.
c. A solid forms.
Problem 2
Balance the following equation in standard form and determine the sum of the coefficients.
a.6
b.4
c.3
d.14
e.7
Problem 3
Balance this equation using the smallest possible integers, S + HNO3→ H2SO4 + NO2 + H2O. What is the coefficient of water.
a.2
b.6
c.8
d. 1
Problem 4
When the following equation is balanced using the smallest possible integers, what is the coefficient of oxygen gas?
C7H16(g) + O2(g) → CO2(g) + H2O(g)
a.5
b.11
c.2
d.14
e.8
Problem 5
True or false? The equation N2 + 3H2→ 2NH3 means that 1 g of N2 reacts with 3 g of H2 to form 2 g of NH3.
Problem 6
Which of the following statements is not true of balancing a chemical equation?
a.Subscripts in the reactants must be conserved in the products.
b.The law of conservation of matter must be followed.
c.Phases are often shown for each compound but are not critical to balancing an equation.
d.All of the above statements (a-d) are true.
e.Coefficients are used to balance the atoms on both sides.
Problem 7
CH4(g) + 2O2(g) → CO2(g) + 2H2O(g)
a.oxidation-reduction
b.two of these
c.synthesis
d. decomposition
e.combustion
Problem 8
Classify the following reaction:
2Mg(s) + O2(g) → 2MgO(s)
a.synthesis
b.oxidation-reduction
c. a-c are all correct.
d.combustion
e.two of the above
Problem 9
The equation 2Ag2O(s) → 4Ag(s) + O2(g) is a(n) ______________ reaction.
a.synthesis
b.two of these
c. oxidation-reduction
d.decomposition
e.combustion
Problem 10
The reaction 2K(s) + Br2(l) → 2KBr(s) is a(n) ______________ reaction.
a.acid-base
b.oxidation-reduction
c.precipitation
d. single-replacement
e.double-displacement
Problem 11
When the following equation is balanced in standard form, what is the coefficient in front of the H2O?
C8H18(g) + O2(g) CO2(g) + H2O(g)
a.8
b.18
c.16
d.25
e.1
Problem 12
Which of the following is a strong acid?
a.phosphoric acid
b.acetic acid
c.hydrofluoric acid
d.lactic acid
e.hydrochloric acid
Problem 13
Which of the following statements is not true?
a.Two nonmetals can undergo an oxidation-reduction reaction.
b.A metal-nonmetal reaction involves electron transfer.
c.When two nonmetals react, the compound formed is ionic.
d.A metal-nonmetal reaction can always be assumed to be an oxidation-reduction reaction.
e.When a metal reacts with a nonmetal, an ionic compound is formed.
Problem 14
17.7 g of Mg represents how many moles?
a.none of these
b.1.37 mol
c.42.0 mol
d.4.30 × 102 mol
e.0.728 mol
Problem 15
21.2 g of oxygen contains
a.none of the above
b.1.28 × 1025 oxygen molecules
c.7.98 × 1023 oxygen atoms
d.42 amu
e.1.33 mol of oxygen molecules
Problem 16
45 atoms of calcium weigh
a.1.804 × 103 g
b.900 amu
c.900 g
d.1.804 × 103 amu
e.2.71 × 1025 amu
Problem 17
8.55 x 10-3 moles of an unknown compound has a mass of 0.257 g. The compound could be:
a.C5H12
b.CH4
c.C3H8
d.C2H6
e.C4H10
Problem 18
A 1.73-mole sample of H2O2 weighs
a. 31.2 amu
b. 31.2 g
c. 1.73 g
d. 58.8 g
e 35.7 g
Problem 19
A certain compound has an empirical formula of NH2O. Its molar mass is between 55 and 65 g/mol. Its molecular formula is
a N2H4O2
b N2H2O2
c NH2O
d not calculable
Problem 20
A certain compound is found to have the percent composition (by mass) of 85.63% C and 14.37% H. The molecular formula contains 3 carbon atoms. How many hydrogen atoms are contained in a molecular of this compound?
A 8
b3
c 2
d 4
e 6
Problem 21
A compound is composed of element X and hydrogen. Analysis shows the compound to be 80% X by mass, with three times as many hydrogen atoms as X atoms per molecule. Which element is element X?
A F
b none of these
c He
d S
e C
Problem 22
Calculate the mass of 5.333 moles of silver nitrate.
a.none of these
b.906.1 g
c.820.8 g
d.31.9 g
e.3.139 × 10-2 g
Problem 23
Convert: 3.577 mol K2O = _____________ g K2O
a.26.33
b 3.577
c.337.0
d 3.797 × 10-2
e 2.154 × 1024
Problem 24
Convert: 9.41 mol Cu(NO3)2 = ____________ g Cu(NO3)2
a. none of these
b 1.77 × 103
c 1.61 × 103
d 5.02 × 10-2
e 19.9
Problem 25
Determine the percentage composition (by mass) of tin in SnCl2.
a.62.6 %
b.77.0 %
c 38.5 %
d 61.5 %
e 18.7 %
Problem 26
The empirical formula of styrene is CH; its molar mass is 104.1 g/mol. What is the molecular formula of styrene?
a.C8H8
b.C2H4
c C6H6
d C10H12
Problem 27
What is the molar mass of Li3PO4?
a 83.79 g/mol
b 115.79 g/mol
c 108.85 g/mol
d 6.02 × 1023 g/mol
e 84.82 g/mol
Problem 28
Which represents the greatest mass?
a.1.0 mol P
b.1.0 mol K
c. all the same
d.1.0 mol Al
e.1.0 mol I
Problem 29
True or false? One atomic mass unit (amu) is the mass (in grams) of one mole of the substance.
Problem 30
True or false? The empirical formula and the molecular formula for a compound cannot be the same.
Problem 31
True or false? The mole can be defined as the number equal to the number of oxygen atoms in 32.00 g of oxygen.
Problem 32
An excess of Al and 9.7 mol of Br2 are reacted according to the equation
How many moles of AlBr3 will be formed assuming 100% yield?
a.4.9 mol
b.6.5 mol
c.9.7 mol
d.14.6 mol
e.3.2 mol
Problem 33
Calculate the mass of water produced when 6.25 g of methane, CH4, reacts with an excess of oxygen in the following unbalanced reaction.
a. 7.02 g H2O
b 0.78 g H2O
c. 14.0 g H2O
d.2.25 × 102 g H2O
e.0.347 g H2O
Problem 34
Consider the equation: . The molar mass of B is 50.0 g/mol. Which of the following statements is true when equal masses of A and B are reacted?
a.If the molar mass of A is less than the molar mass of B, then B must determine how much C is produced.
b. If the molar mass of A is greater than the molar mass of B, then B must determine how much C is produced.
c.If the molar mass of A is greater than the molar mass of B, then A must determine how much C is produced.
d.If the molar mass of A is less than the molar mass of B, then A must determine how much C is produced.
e If the molar mass of A is the same as the molar mass of B, then A and B react in a perfect stoichiometric ratio and both determine how much C is produced.
Problem 35
Consider the following unbalanced equation:
How many moles of water are needed to react with 232. g of Al4C3?
a.0.620 mol
b.0.134 mol
c 19.3 mol
d 1.61 mol
e 348. mol
Problem 36
Tin(II) fluoride is added to some dental products to help prevent cavities. Manufacturers have to make the tin(II) fluoride first, though, before they can add it to their products.
How many grams of tin(II) fluoride can be made from 58.0 g of hydrogen fluoride if there is plenty of tin available to react?
a. 908. g
B 227. g
c 116. g
d 454. g
e 1.45 g
Problem 37
What mass of carbon dioxide will be produced when 12.9 g of butane reacts with an excess of oxygen in the following reaction?
a. none of these
b 39.1 g CO2
c 4.88 g CO2
d 78.1 g CO2
e 51.6 g CO2
Problem 38
True or false? A balanced chemical equation is one that has the same number of moles of molecules on each side of the equation.
Problem 39
True or false? A mole ratio is used to convert the moles of a starting substance to the moles of a desired substance.
Problem 40
True or false? The equation can be interpreted by saying that 1 mol of N2 reacts with 3 mol of H2 to form 2 mol of NH3.
Problem 41
A hydrogen balloon is at 25oC, 1.00 atm and has a volume of 1.00 L. How many grams of argon gas must be added to the hydrogen balloon to achieve a volume of 3.84 L at constant temperature and pressure?
a 4.64 g
b 93.9 g
c none of these
d 6.27 g
e 7.91 g
Problem 42
A sample of an ideal gas containing 0.918 mol is collected at 742 torr pressure and 31°C. Calculate the volume.
aL
b 23.5 L
cL
d none of these
e 2.39 L
Problem 43
A sample of oxygen gas (O2) has a volume of 7.86 L at a temperature of 19oC and a pressure of 1.38 atm. Calculate the moles of O2 molecules present in this gas sample.
A none of these
B 0.226 mol
C 6.96 mol
D 0.905 mol
E 0.453 mol
Problem 44
An oxygen sample has a volume of 9.77 L at 27°C and 800.0 torr. How many oxygen molecules does it contain?
Problem 45
Avogadro's law states that:
a The volume of a fixed amount of gas is indirectly proportional to its temperature in Kelvin at constant pressure.
b The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
c The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
d Equal amounts of gases occupy the same volume at constant temperature and pressure.
e The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
Problem 46
Boyle's law states that:
a Equal amounts of gases occupy the same volume at constant temperature and pressure.
b The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
c The volume of a fixed amount of gas is proportional to its pressure at constant temperature.
d The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
e The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
Problem 47
Charles's law states that:
a.The volume of a fixed amount of gas is inversely proportional to its pressure at constant temperature.
b. The total pressure of a mixture of gases is the simple sum of the partial pressure of all of the gaseous compounds.
C The volume of a fixed amount of gas is directly proportional to its temperature in Kelvin at constant pressure.
D The volume of a fixed amount of gas is indirectly proportional to its temperature in Kelvin at constant pressure.
E Equal amounts of gases occupy the same volume at constant temperature and pressure.
Problem 48
A solution has [H+] = 4.7 × 10-8M. The pH of this solution is
a.9.80
b.7.33
c.6.01
d. none of these
e.6.67
Problem 49
A solution has a pH of 3.66. The pOH of this solution is
a.10.34
b.none of these
c.10.24
d.3.76
e. 3.66
Problem 50
A solution where [H+] = 10-13M is ______________.
Select one:
A acidic
B basic
C strongly acidic
d.neutral
e.two of these
Problem 51
Calculate the [H+] in a solution that has a pH of 2.39.
aM
b none of these
c 11.61 M
d 2.39 M
eM
Problem 52
What is the pH of a 3.6 M solution of HClO4?
a. 0.56
b.13.44
c.-0.56
d. 14.56
e. minus infinity
Problem 53
What is the pH of a solution that has [OH-] = .
a.3.84 M
b.1.92 M
c. none of these
d. 10.16 M
e.6.90 M
Problem 54
Which of the following is not a strong acid?
a. HClO4
b.H2SO4
c.CH3COOH
d.HCl
e.HNO3
Problem 55
Which of the following statements is/are correct?
a.None of the above statements (a-c) are correct.
b.In a basic solution, [OH-] > [H+].
c.All of the above statements (a-c) are correct.
d.In an acidic solution, [H+] > [OH-].
e.In a neutral solution, [H+] = [OH-].
Problem 58
How many lone pairs of electrons are in the Lewis structure for compound, HF?
a.3
b.4
c.1
d.0
e.none of these
Problem 59
How many of the following will have Lewis structures with multiple bonds?
CO, CO2, CO32-, N2, O2
a.2
b.1
c.3
d.5
e.4
Problem 60
The number of polar covalent bonds in SF4 is
a.none of these
b.3
c.2
d.4
e.1
Problem 61
Which has a bent structure?
a.NH3
b.CO2
c.CaCl2
d.O2
e.H2O
Problem 62
Which has a linear structure?
a.SCl2
b.OF2
c.CO2
d.CaCl2
e.SO2
Problem 63
Which has a planar structure?
a.CO32-
b.H3O+
c.CH4
d.NF3
e.SO32-
Problem 64
Which has a tetrahedral structure?
a.CO32-
b.NH3
c.SO3
d.CH4
e.SO32-
Problem 65
Which has a trigonal pyramid structure?
a.NO3-
b.SO32-
c.CO32-
d.CH4
e.SO3
Problem 66
Which of the following bonds does not have a dipole moment?
a.C-H
b.B-F
c.Br-H
d.F-F
e.F-H
Problem 67
Which of these has more than one reasonable resonance structure?
a.SiCl4
b.BH4-
c.NO3-
d.N2H4
e.PH3
Problem 68
True or false? A bond is a force that holds groups of two or more atoms together and makes them function as a unit.
True
False
Problem 69
True or false? CH4 has ionic bonds.
True
False
Problem 70
True or false? Covalent bonding occurs when a metal reacts with a nonmetal.
True
False.