• CHEM101_MH_V4
• Topic 3: Stoichiometry
Started on Friday, April 15, 2022, 7:00 PM
State Finished
Completed on Friday, April 15, 2022, 7:25
... [Show More] PM
Time taken 25 mins 47 secs
Grade 115.00 out of 115.00 (100%)
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Question 1
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Which of the following cannot be separated into simpler substances by chemical means?
Select one:
a. Element
b. Emulsion
c. Compound
d. Homogeneous mixture
e. Heterogeneous mixture
Question 2
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What is a unifying principle that explains a body of experimental observations?
Select one:
a. Law
b. Hypothesis
c. Theory
d. Phenomena
e. Prediction
Question 3
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Which of the following is a chemical change?
Select one:
a. Boiling water
b. Melting wax
c. Broiling a steak on a grill
d. Condensing water vapor into rainfall
e. Carving a piece of wood
Question 4
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If a liquid contains 60% sugar and 40% water throughout its composition then what is it called?
Select one:
a. Solute
b. Compound
c. Homogeneous mixture
d. Heterogeneous mixture
e. Solvent
Question 5
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Which one of these represents a physical change?
Select one:
a. Water, when heated, forms steam.
b. Bleach turns hair yellow.
c. Sugar, when heated, becomes brown.
d. Milk turns sour.
e. Apples, when exposed to air, turn brown.
Question 6
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The dark meat of a 20-pound turkey requires an internal temperature of 180°F to be fully cooked. What minimum temperature reading should be displayed on a food thermometer that only measures in degrees Celsius?
Select one:
a. 82°C
b. 354°C
c. 261°C
d. –192°C
e. –310°C
Question 7
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Which is correct if 52.068881 is rewritten in scientific notation and rounded to three significant figures?
Select one:
a. 5.21 × 10–1
b. 5.20 × 10–1
c. 5.21 × 101
d. 5.20 × 101
e. 5.21 × 102
Question 8
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How many significant figures are in 0.006570?
Select one:
a. 3
b. 4
c. 5
d. 6
e. 7
Question 9
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What element is represented by X in the atomic symbol notation ?
Select one:
a. Iridium
b. Platinum
c. Palladium
d. Selenium
e. Magnesium
Question 10
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Which of the following is a metalloid?
Select one:
a. Carbon, C, Z = 6
b. Sulfur, S, Z = 16
c. Germanium, Ge, Z = 32
d. Iridium, Ir, Z = 77
e. Bromine, Br, Z = 35
Question 11
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The elements in Group 7A are known by what name?
Select one:
a. Transition metals
b. Halogens
c. Alkali metals
d. Alkaline earth metals
e. Noble gases
Question 12
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Which of these materials are usually poor conductors of heat and electricity?
Select one:
a. Metals
b. Metalloids
c. Nonmetals
d. Alkaline earth metals
e. Alkali metals
Question 13
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The scientist who determined the magnitude of the electric charge on the electron was
Select one:
a. John Dalton
b. Robert Millikan
c. J. J. Thomson
d. Henry Moseley
e. J. Burdge
Question 14
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Which of these compounds is most likely to be ionic?
Select one:
a. KF
b. CCl4
c. CS2
d. CO2
e. ICl
Question 15
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The compound, P4S10, is used in the manufacture of safety matches. What is its name?
Select one:
a. phosphorus sulfide
b. phosphoric sulfide
c. phosphorus decasulfide
d. tetraphosphorus decasulfide
e. phosphorus sulfite
Question 16
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Which one of these species is an ion?
Select one:
a. B3+
b. NaCl
c. He
d. 14C
e. None of these species is an ion.
Question 17
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What is the formula for the permanganate ion?
Select one:
a. MnO2–
b. MnO4–
c. MgO42–
d. Mn2O7–
e. MgO22–
Question 18
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Calculate the mass of 3.00 moles of CF2Cl2.
Select one:
a. 3.00 g
b. 174 g
c. 363 g
d. 1.81 × 1024 g
e. 40.3
Question 19
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How many grams are contained in a 0.183 mol sample of ammonium phosphate?
Select one:
a. 1.23 × 10–3 g
b. 617 g
c. 20.7 g
d. 27.3 g
e. 815.1 g
Question 20
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Which of the following substances contains the greatest mass of carbon?
Select one:
a. 100 g CH4
b. 100 g C2H4
c. 100 g CCl4
d. 100 g CH2Cl2
e. 100 g CO2
Question 21
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What is the molar mass of nicotine, C10H14N2?
Select one:
a. 134 g/mol
b. 148 g/mol
c. 158 g/mol
d. 210 g/mol
e. 162 g/mol
Question 22
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Once the following equation is balanced with the smallest set of whole number coefficients, what is the sum of the coefficients? (Don't forget to include coefficients of one.)
___ CH4 + ___ Cl2 → ___ CCl4 + ___ HCl
Select one:
a. 4
b. 6
c. 8
d. 10
e. 12
Question 23
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What is the theoretical yield of chromium that can be produced by the reaction of 40.0 g of Cr2O3 with 8.00 g of aluminum according to the chemical equation below?
2Al + Cr2O3 → Al2O3 + 2Cr
Select one:
a. 7.7 g
b. 15.4 g
c. 27.4 g
d. 30.8 g
e. 49.9 g
Question 24
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What is the coefficient of H2O when the following equation is properly balanced with the smallest set of whole numbers?
___ Al4C3 + ___ H2O → ___ Al(OH)3 + ___ CH4
Select one:
a. 3
b. 4
c. 6
d. 12
e. 24
Question 25
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If 13.9 g of oxygen react with 33.7 g of calcium to produce calcium oxide, what is the limiting reactant and what mass of calcium oxide is produced?
Select one:
a. Calcium is the limiting reactant and 47.2 g of calcium oxide are produced
b. Oxygen is the limiting reactant and 24.4 g of calcium oxide are produced
c. Calcium is the limiting reactant and 60.6 g of calcium oxide are produced
d. Oxygen is the limiting reactant and 48.7 g of calcium oxide are produced
e. Calcium is the limiting reactant and 23.6 g of calcium oxide are produced [Show Less]