QUESTION 1 When propane undergoes complete combustion, the products are carbon dioxide and water

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QUESTION 1

1. When propane undergoes complete combustion, the products are carbon dioxide and water.
           __ C₃H₈(g) + __ O₂(g) → __ CO₂(g) + __ H₂O(g)
   What are the respective coefficients when the equation is balanced with the smallest whole numbers?

   		1, 3, 1, 3
   		1, 3, 3, 1
   		1, 5, 3, 4
   		1, 1, 1, 1
   		2, 5, 3, 4

2 points   

QUESTION 2

1. What is the balanced chemical equation for the complete combustion of benzoic acid, C₆H₅CO₂H, to form carbon dioxide and water?

   		2 C6H5CO2H(s) + 15 O2(g) → 14 CO2(g) + 6 H2O(g)
   		C6H5CO2H(s) → 6 C(s) + CO2(g) + 3 H2(g)
   		C6H5CO2H(s) + 8 O2(g) → 7 CO2(g) + 3 H2O(g)
   		C6H5CO2H(s) → 7 CO2(g) + 3 H2O(g)
   		C6H5CO2H(s) + O2(g) → CO2(g) + H2O(g)

2 points   

QUESTION 3

1. Which of the following statements is/are CORRECT?

   	1.	Water soluble ionic compounds, such as NaCl, are strong electrolytes.
   	2.	Some molecular compounds, such as HCl, are strong electrolytes.
   	3.	Some molecular compounds, such as acetic acid, are weak electrolytes.

   		1 and 2
   		3 only
   		2 only
   		1, 2, and 3
   		1 only

2 points   

QUESTION 4

1. Which one of the following compounds is a nonelectrolyte when dissolved in water?

   		HCl
   		NaCH3CO2
   		CaCl2
   		Cu(NO3)2
   		CCl4

2 points   

QUESTION 5

1. A precipitate will form when aqueous Pb(NO₃)₂ is added to an aqueous solution of ____.

   		NaCH3CO2
   		NaI
   		Pb(ClO4)2
   		Cu(NO3)2
   		KNO3

2 points   

QUESTION 6

1. What is the net ionic equation for the reaction of aqueous sodium hydroxide and aqueous iron(II) chloride?

   		Fe2+(aq) + OH–(aq) → FeOH+(s)
   		Fe2+(aq) + 2 OH–(aq) → Fe(OH)2(s)
   		Na+(aq) + OH–(aq) → NaOH(s)
   		Fe2+(aq) + 2 Cl–(aq) → FeCl2(s)
   		Na+(aq) + Cl–(aq) → NaCl(s)

2 points   

QUESTION 7

1. Which of the following compounds is a weak base?

   		NH3
   		CH3CO2H
   		NaOH
   		LiCl
   		H2CO3

2 points   

QUESTION 8

1. What are the spectator ions in the reaction between aqueous hydrobromic acid and aqueous sodium hydroxide?

   		H+ and OH–
   		Na+ only
   		H+, Br–, Na+, and OH–
   		Na+ and Br–
   		Br– only

2 points   

QUESTION 9

1. Which of the following chemical equations show oxidation-reduction reactions?

   	1.	Mg(s) + I 2(aq) → MgI 2(s)
   	2.	Pb(ClO 4) 2(aq) + 2 KI(aq) → PbI2(s) + 2 KClO 4(aq)
   	3.	Fe 2O 3(s) + 3 CO(g) → 2 Fe(s) + 3 CO 2(g)

   		1 only
   		2 only
   		1 and 3
   		2 and 3
   		1 and 2

2 points   

QUESTION 10

1. When strongly heated, boric acid breaks down to boric oxide and water. What mass of boric oxide is formed from the decomposition of 15.0 g B(OH)₃?
           2 B(OH)₃(s) → B₂O₃(s) + 3 H₂O(g)

   		16.9 g
   		8.44 g
   		7.50 g
   		33.8 g
   		15.0 g

2 points   

QUESTION 11

1. What mass of water is produced by the complete combustion of 2.68 grams of ethanol, C₂H₅OH?

   		1.05 g
   		1.17 g
   		0.439 g
   		3.14 g
   		20.6 g

2 points   

QUESTION 12

1. How many moles of sodium bromide can be produced from the reaction of 1.03 moles of sodium with 0.650 moles of bromine gas?
           2 Na(s) + Br₂(g) → 2 NaBr(s)

   		0.650 mol
   		1.03 mol
   		0.515 mol
   		2.06 mol
   		1.30 mol

2 points   

QUESTION 13

1. How many moles of Mg₃P₂(s) can be produced from the reaction of 0.14 mol Mg(s) with 0.020 mol P₄(s)?
           6 Mg(s) + P₄(s) → 2 Mg₃P₂(s)

   		0.14 mol
   		0.047 mol
   		0.42 mol
   		0.040 mol
   		0.020 mol

2 points   

QUESTION 14

1. Aspirin is produced by the reaction of salicylic acid (M = 138.1 g/mol) and acetic anhydride (M = 102.1 g/mol).
           C₇H₆O₃(s) + C₄H₆O₃() → C₉H₈O₄(s) + C₂H₄O₂()
   If 2.04 g of C₉H₈O₄ (M = 180.2 g/mol) is produced from the reaction of 3.03 g C₇H₆O₃ and 4.01 g C₄H₆O₃, what is the percent yield?

   		67.3%
   		28.8%
   		29.0%
   		51.6%
   		50.9%

2 points   

QUESTION 15

1. Naphthalene, a hydrocarbon, has an approximate molar mass of 128 g/mole. If the combustion of 0.6400 g naphthalene produces 0.3599 g H₂O and 2.1977 g CO₂, what is the molecular formula of this compound?

   		C10H8
   		C9H18
   		C11H7
   		C8H32
   		C9H20

2 points   

QUESTION 16

1. If 4.49 g NaNO₃ is dissolved in enough water to make 250.0 mL of solution, what is the molarity of the sodium nitrate solution?

   		5.28 × 10–2 M
   		1.32 × 10–2 M
   		1.80 × 10–2 M
   		18.0 M
   		2.11 × 10–1 M

2 points   

QUESTION 17

1. How many liters of 0.1107 M KCl(aq) contain 2.50 g of KCl?

   		3.71 × 10−3 L
   		0.303 L
   		3.30 L
   		0.277 L
   		5.94 × 10−4 L

2 points   

QUESTION 18

1. Zn reacts with hydrochloric acid.
           Zn(s) + 2 HCl(aq) → ZnCl₂(aq) + H₂(g)
   What volume of 3.05 M HCl(aq) will react with 25.0 g Zn(s)?

   		0.251 L
   		2.33 L
   		0.0627 L
   		4.01 L
   		0.125 L

2 points   

QUESTION 19

1. At 0.982 atm, the height of mercury in a barometer is 0.746 m. If the mercury were replaced with ethanol, what height of ethanol (in meters) would be supported at this pressure? The densities of Hg and ethanol are 13.5 g/cm³ and 0.789 g/cm³, respectively.

   		0.760 m
   		13.0 m
   		0.0436 m
   		12.8 m
   		0.946 m

2 points   

QUESTION 20

1. If the volume of a confined gas is expanded to four times the original volume while its temperature remains constant, what change will be observed?

   		The pressure of the gas will remain unchanged.
   		The pressure of the gas will increase to twice its original value.
   		The pressure of the gas will decrease to 1/2 its original value.
   		The pressure of the gas will increase to four times its original value.
   		The pressure of the gas will decrease to 1/4 its original value.

2 points   

QUESTION 21

1. Which of the following relationships is/are CORRECT for gases?

   	1.	The amount of a gas (in moles) is inversely proportional to its volume (at constant temperature and pressure).
   	2.	The volume of a gas is directly proportional to its temperature in kelvin (at constant pressure and moles).
   	3.	The pressure of a gas is inversely proportional to its temperature in kelvin (at constant volume and moles).

   		1 and 2
   		3 only
   		2 only
   		2 and 3
   		1 only

2 points   

QUESTION 22

1. If 0.357 g of CH₄ gas is introduced into an evacuated 1.75 L flask at 25 °C, what is the pressure inside the flask? (R = 0.08206 L⋅atm/mol⋅K)

   		0.311 atm
   		0.419 atm
   		0.952 atm
   		4.99 atm
   		0.261 atm

2 points   

QUESTION 23

1. The pressure of O₂ in a 15.0 L flask is 322 mm Hg at 44 °C. What mass of O₂ is in the flask? (R = 0.08206 L⋅atm/mol⋅K)

   		5.80 g
   		7.82 g
   		15.2  g
   		0.244 g
   		56.3 g

2 points   

QUESTION 24

1. A mass of 1.37 g of an unknown gas is introduced into an evacuated 1.70 L flask. If the pressure in the flask is 0.814 atm at 98 °C, which of the following gases might be in the flask? (R = 0.08206 L⋅atm/mol⋅K)

   		C4H10
   		CH4
   		C2H2
   		C3H8
   		C2H6

2 points   

QUESTION 25

1. Ozone decomposes to oxygen according to the balanced chemical equation below.
           2 O₃(g) → 3 O₂(g)
   If the rate of disappearance of ozone is –2.4 × 10^–6 M/s, what is the rate of formation of oxygen?

   		1.6 × 10–6 M/s
   		–2.4 × 10–6 M/s
   		2.4 × 10–6 M/s
   		3.6 × 10–6 M/s
   		7.2 × 10–6 M/s

2 points   

QUESTION 26

1. Which of the following factors are likely to affect the rate of a chemical reaction?

   	1.	the presence of a catalyst
   	2.	the temperature of the reactants
   	3.	the physical state (solid, liquid, or gas) of the reactants

   		1 only
   		3 only
   		1, 2, and 3
   		1 and 3
   		2 only

2 points   

QUESTION 27

1. What is the name given to a substance that increases the rate of a chemical reaction but is not itself consumed?

   		catalyst
   		intermediate
   		reactant
   		enthalpy
   		rate constant