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Midterm Exam 1 B
1.
Which Exam are you taking?
a) Midterm 1 A
d) Midterm 1 D
2.
b) Midterm 1 B
e) Midterm 1 E
c) Midterm 1 C
Crystalline potassium hydrogen phthalate KHC8H4O4 is used to standardize basic
solutions. If 1.548 g of this salt is titrated with a solution of Ca(OH)2, the end
point is reached when 42.37 mL of the solution has been added. What is the
molarity of the Ca(OH)2 solution? (Atomic weights: C = 12.01, O = 16.00, H =
1.008, Ca = 40.08, K = 39.10)
2 KHC8H4O4 + Ca(OH)2 → Ca(KC8H4O4)2 + 2 H2O
a) 4.457 x 10-2
b) 6.225 x 10-2
d) 1.243 x 10-1
e) 8.954 x 10-2
c) 8.915 x 10-2
Closest Answer
3.
Determine the mass (g) of solute required to form 500.0 mL of a 0.480 M MgCl2.
(Atomic weights: Mg = 24.30, Cl = 35.45)
a) 19.8
b) 21.1
c) 22.8
d) 24.2
e) 26.3
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4.
The equation for the reduction of iron ore in a blast furnace is given below. How
many kilograms of iron can be produced by the reaction of 7.00 kg of Fe2O3 and
3.00 kg of CO? (Atomic weights: Fe = 55.85, O = 16.00, C = 12.01)
Fe2O3 + 3 CO → 2 Fe + 3 CO2
a) 3.65
5.
b) 3.98
c) 4.20
d) 4.32
e) 4.74
Balance the following equation. What is the sum of the coefficients of the
reactants and products?
__I2O5 + __BrF3 → __ IF5 + __O2 + __ Br2
a) 25
6.
b) 32
c) 45
d) 56
e) 63
During naval battle in the South Pacific in WW2, the U.S. navy produced
smokescreens by spraying titanium tetrachloride into the moist air to produce
TiO2. How many grams of TiO2 are produced from 14.4 moles of TiCl4?
(Atomic weights: Ti = 47.90, O = 16.00)
TiCl4 + 2 H2O → TiO2 + 4 HCl
a) 5.68
b) 79.9
d) 1.15 x 103
e) 2.30 x 103
c) 5.75 x 102
2
7.
A package of aluminum foil contains 12 ounces of aluminum ( 1 oz = 28.4 g).
How many moles of aluminum atoms are in the package?
(Atomic weight: Al = 26.98)
a) 1.2
8.
c) 0.45
d) 12
e) 13
Aziridine contains only carbon, hydrogen and nitrogen. When a 0.4622 g sample
is burned completely in oxygen, 0.9673 g of CO2 and 0.3960 g of H2O are
formed. What is the empirical formula?
(Atomic weights: C = 12.01, H = 1.008, O = 16.00, N = 14.01)
a) C2H3N
9.
b) 4.5
b) C2H4N
c) CHN
d) C2H4N3
e) C3H6N
An oxide of lead is converted by hydrogen gas to lead metal and water. One mole
of the oxide reacts with 8.1 g of H2 and forms 622 g of lead. What is the
empirical formula of the oxide?
(Atomic weights: Pb = 207.2, O = 16.00, H = 1.008)
a) PbO
b) PbO2
c) PbO3
d) Pb3O4
e) Pb2O5
3
10.
Which of the following organic compounds has the lowest molecular weight?
(Atomic weights: C = 12.01, O = 16.00, F = 19.00, H = 1.008)
a) C4H8F2O2
d) C4H7FO3
11.
c) C5H8FO2
A sample of the compound M2SO4 weighing 0.1688 g reacts with BaCl2 to give
0.2772 g BaSO4. What is the atomic weight of the element M? (Atomic weights:
S = 32.06, O = 16.00, Ba 137.3)
a) 6.94
12.
b) C3H5F3O2
e) C3H6F2O3
b) 23.0
c) 39.1
d) 24.3
e) 40.1
Silicon (atomic weight 28.0855) has three naturally-occurring isotopes with
isotopic weights 27.97693, 28.97649 and 29.97376. The abundance of the
lightest isotope is 92.21%. What is the percentage abundance of the heaviest
isotope?
a) 6.3
b) 5.2
c) 3.9
d) 3.1
e) 2.6
4
13.
What is the chemical name of Sc2(CrO4)3?
a) scandium (II) chromate
c) scandium (III) chromate
e) scandium (II) chromite
14.
What is the symbol for the bisulfite ion?
a) HSO4–
15.
b) scandium (II) dichromate
d) scandium (III) dichromate
b) HSO3–
c) HSO32–
d) HSO42–
e) H2SO4–
32 S2The species 16
contains:
a) 16 protons and 18 neutrons
b) 18 protons and 16neutrons
c) 16 protons and 18 electrons
d) 18 electrons and 32 neutrons
e) 16 protons and 16 electrons
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16.
Which of the following samples has the largest mass?
a) 25 g lead (density = 11.3 g/cm3)
b) 15 cm3 aluminum (density = 2.70 g/cm3)
c) 4.0 cm3 chromium (density = 7.20 g/cm3)
17.
18.
Oil spreads on water to form a film 110 nm thick. How many square kilometers
of ocean will be covered by a slick formed from one barrel of oil (126 liters)?
a) 1.15
b) 1.15 x 106
c) 1.15 x 104
d) 1.15 x 102
e) 1.15 x 1010
A crucible is known to weigh 24.6132 g. Three students in the class determine
the weight of the crucible by repeated weighing on a simple balance. Using the
following information, which student has done the most precise determination?
Trial 1
a)
b)
c)
24.8
24.8
24.5
Trial 2
Trial 3
Trial 4
24.9
24.0
24.1
24.8
24.2
24.5
24.9
24.1
24.1
Trial 5
24.8
24.3
24.3
6
19.
Do the indicated arithmetic and give the answer to the correct number of
significant figures.
(0.00015 x 54.6) + 1.0020
a) 1.0
b) 1.01
c) 1.01019
d) 1.010
e) 1.0102
20.
Gases and liquids share the property of __________________.
a) Compressibility
b) Definite volume
c) Incompressibility
d) Indefinite shape
e) Definite shape
21.
Which one of the following is not an intensive property?
a) Density
b) Temperature
c) Melting point
d) Mass
e) Boiling mass
Boiling Point - this typo was
corrected on the board
during the exam.
7
22.
The name of PCl3 is _______.
a) Potassium chloride
b) Phosphorus trichloride
c) Phosphorous (III) chloride
d) Monophosphorous trichloride
e) Trichloro potassium
23.
When aqueous solutions of ___________ are mixed, a precipitate forms.
a) NiBr2 and AgNO3
b) NaI and KBr
c) K2SO4 and CrCl3
d) KOH and KNO3
e) Li2CO3 and NaI
24.
Based on the activity series, which one of the reactions below will occur?
a) Zn (s) + MnI2 (aq) → ZnI2 (aq) + Mn (s)
b) SnCI2 (aq) + Cu (s) → Sn (s) + CuCI2 (aq)
c) 2AgNO3 (aq) + Pb (s) → 2Ag (s) + Pb(NO3)2(aq)
d) 3Hg (1) + 2Cr(NO3)3(aq) → 3Hg(NO3)2 + 2Cr (s)
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25.
The spectator ions in the reaction between aqueous perchloric acid and
aqueous barium hydroxide are _________.
a) OH– and CIO4–
b) H+,OH–,CIO4–, and Ba2+
c) H+ and OHd) H+ and Ba2+
e) CIO4– and Ba2+
26.
Which are the following are weak electrolytes?
3)NH3
1) HCl
2) HC2H3O2
a)
b)
c)
d)
e)
4) KCl
HCl, KCl
HCl, HC2H3O2, NH3, KCl
HC2H3O2, NH3, KCl
HC2H3O2, NH3
HCl, HC2H3O2, KCl
9