Deck 4: Chemical Reactions

Question 1

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? K2O + H2O → KOH

A) 2
B) 6
C) 3
D) 8
E) 4

Answer 1

4

Question 2

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Na + HCl → NaCl + H2

A) 7
B) 4
C) 2
D) 10
E) 9

Answer 2

7

Question 3

When the equation K2S2O3 + I2 → K2S4O6 + KI is balanced with the smallest integer coefficients, the coefficient of KI is:

A) 2
B) 1
C) 3
D) 4
E) 5

Answer 3

2

Question 4

A formula is a shorthand way of representing a chemical reaction.

Question 5

How many grams of N2 are required to react with 2.30 moles of Mg in the following process? 3 Mg + N2 → Mg3N2? (Mg = 24.3 g/mol, N = 14.0 g/mol)

A) 21.5 g
B) 0.767 g
C) 64.4 g
D) 0.027 g
E) 193.2 g

Question 6

In a chemical equation, Δ above the yield sign means the reaction will produce heat.

Question 7

The numbers in front of formulas in balanced equations are called stoichiometric coefficients.

Question 8

How many moles of H3PO4 are produced when 20.0 g of HCl are produced by the reaction PCl5 + 4 H2O → H3PO4 + 5 HCl?

A) (20.0/36.5) g
B) (20.0/35.5)/5 g
C) (20.0/36.5)/5 g
D) (20.0/98.0) g
E) (20.0/98.0)/5 g

Question 9

For the reaction 2 Al + Fe2O3 → Al2O3 + 2 Fe, 2.5 g of Al (27.0 g/mol) and 7.2 g of Fe2O3 (159.8 g/mol) produce how many g of Fe (55.9 g/mol)?

A) 2.5 (55.9/27.0) g
B) 2.5 (55.9)(2)/(27.0)(2) g
C) 7.2 (55.9)(2)/159.8 g
D) 7.2 (55.9/159.8) g
E) 2.5 (55.9/159.8) g

Question 10

In a solution of alcohol and water that is 70% water, alcohol is the solvent.

Question 11

A chemical equation is a shorthand way of representing a chemical reaction.

Question 12

What is the sum of the coefficients in the balanced equation that represents the complete combustion of the relatively new gasoline additive "MTBE," for which the molecular formula is C5H12O?

A) 39
B) 37
C) 29
D) 24
E) 20

Question 13

The reactant that is in excess determines the amount of products formed.

Question 14

In a balanced equation, the number of atoms of each element in the products must equal to the number of atoms of each element in the reactants.

Question 15

Molarity is defined as moles of solute per kg of solution.

Question 16

When the equation CS2 + Cl2 → CCl4 + S2Cl2 is balanced with the smallest integer coefficients, the sum of the coefficients is:

A) 5
B) 6
C) 4
D) 3
E) 7

Question 17

(aq) indicates that the compound is dissolved in alcohol.

Question 18

Stoichiometric factor relates the amounts, in moles, of any two substances involved in chemical reaction.

Question 19

Which metal will produce the most hydrogen per gram of metal?

A) 2 Li + 2 HCl → 2 LiCl + H2
B) Sn + 4 HCl → SnCl4 + 2 H2
C) 2 Fe + 6 HCl →2 FeCl3 + 3 H2
D) Mg + 2 HCl → MgCl2 + H2
E) 2 Cr + 6 HCl → 2 CrCl3 + 3H2

Question 20

When the equation Fe2(C2O4)3 → FeC2O4 + CO2 is balanced with the smallest integer coefficients, the coefficient of CO2 is:

A) 1
B) 2
C) 4
D) 3
E) 5

Question 21

24.0 g of ethane (C2H6) are burned to form CO2 and H2O. How many grams of CO2 are produced?

A) 32.8 g
B) 14.4 g
C) 43.2 g
D) 35.1 g
E) 70.3 g

Question 22

If 85.6 mL of a 6.75 M solution are diluted to 6.20 L with water, what is the concentration of the final solution?

A) 6.75 (6.20/85.6) M
B) 6.75 (8.56/6.20) M
C) 6.75 (6200/85.6) M
D) 6.75 (85.6/6200) M
E) 8.56 (6.20/6.75) M

Question 23

Iron metal reacts with chlorine gas as follows: 2 Fe(s) + 3 Cl2(g) → 2 FeCl3(s)
How many moles of FeCl3 are obtained when 4.6 mol of Cl2 reacts with excess Fe?

A) 3.1 mol
B) 4.6 mol
C) 1.5 mol
D) 2.3 mol
E) 6.9 mol

Question 24

Given the following reaction: Na2SO4(s) + 2 C(s) → Na2S(s) + 2 CO2(g)
How many grams of carbon are required to produce 18.4 g Na2S(s)?

A) 11.3 g
B) 5.66 g
C) 2.83 g
D) 239 g
E) 142 g

Question 25

Gases emitted during volcanic activity often contain high concentrations of hydrogen sulfide and sulfur dioxide. These gases may react to produce deposits of sulfur according to the equation: 2 H2S(g) + SO2(g) → 3 S(s) + 2 H2O(g)
For the complete reaction of 6.41 mol of hydrogen sulfide:

A) 308 g of sulfur is formed
B) 410 g of sulfur dioxide is consumed
C) 231 g of water vapor is produced
D) 320 g of total products result
E) 628 g of total reactants are consumed

Question 26

If 5.97 mL of a solution of NaCl contains 2.54 mg of sodium ion, what is the molarity of the sodium chloride solution?

A) 0.425 M
B) 1.85 × 10-2 M
C) 1.85 × 10-5 M
D) 7.28 × 10-3 M
E) 0.102 M

Question 27

What is the molarity of 10.9 g KCl dissolved in 150.0 mL of water?

A) 0.0727 M
B) 0.146 M
C) 0.975 M
D) 0.0219 M
E) 0.667 M

Question 28

What mass of trisodium phosphate is required to prepare 250.0 mL of a solution that is 0.30 M in sodium ion?

A) 37 g
B) 12 g
C) 7.7 g
D) 4.1 g
E) 3.0 g

Question 29

What volume of 6.0 M sulfuric acid is required for the preparation of 500.0 mL of 0.30 M solution?

A) 100 mL
B) 50 mL
C) 40 mL
D) 30 mL
E) 25 mL

Question 30

For the reaction symbolized as HCl(aq) + NaOH(aq) → NaCl(aq) + H2O(l) water is both:

A) a reactant and the solute
B) a reactant and the solvent
C) a product and the solute
D) a product and the solvent
E) a liquid and the intermediate

Question 31

Which of the following represents a 1.00 M aqueous solution of glucose (C6H12O6)?

A) 90.0 g glucose per 500 mL water
B) 10.0 g glucose per 10.0 mL water
C) 0.180 g glucose per mL solution
D) 0.100 g glucose per mL solution
E) 4.5 g glucose per 4.5 g water

Question 32

52.5 mL of a solution were diluted to a volume of 6.25 L and then had a concentration of 3.16 M. What was the molarity of the initial solution?

A) 3.16(52.5/6.25) M
B) 3.16(6.25/52.5) M
C) (3.16)(52.5)(6.25) M
D) 3.16(52.5/6250) M
E) (6.25)(3.16)/0.0525 M

Question 33

What volume of 2.0 M HCl, in mL, is required to dissolve a 10.0 g piece of Zn? Zn(s) + 2 HCl → ZnCl2 + H2(g)

A) 76 mL
B) 330 mL
C) 170 mL
D) 310 mL
E) 150 mL

Question 34

45.8 mL of a 3.14 M sodium chloride solution were used to react completely with 50.0 mL of an aqueous silver nitrate solution. What is the molarity of the silver nitrate solution?

A) 2.88 M
B) 1.50 M
C) 3.14 M
D) 3.42 M
E) 1.71 M

Question 35

What volume of concentrated acetic acid (CH3CO2H, density 1.05 g mL-1) is needed to prepare 250 mL of a 0.30 M aqueous solution?

A) 4.7 mL
B) 4.3 mL
C) 3.0 mL
D) 2.5 mL
E) 2.2 mL

Question 36

Given the reaction: 2KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O
How many moles of H2SO4 are required to produce 2.0 moles of I2, given the other reactants are in excess?

A) 0.80 mol
B) 1.3 mol
C) 3.2 mol
D) 4.0 mol
E) 1.6 mol

Question 37

How many mL of 0.024 M solution can be produced from 14.1 mL of 3.0 M solution?

A) (14.1)(0.024)(3.0) mL
B) 14.1(0.024/3.0) mL
C) 14.1(3.0/0.024) mL
D) (14.1/0.024)/3.0 mL
E) (0.024×3)/14.1 mL

Question 38

Which of the following processes could theoretically produce the maximum mass of oxygen per gram of metal salt reactant?

A) 2 KClO3 → 2 KCl + 3 O2
B) 4 KO2 + 2 CO2 → 2 K2CO3 + 3 O2
C) 2 Na2O2 + 2 H2SO4 → 2 H2O + O2
D) 2 HgO → 2 Hg + O2
E) NaBrO2 → NaBr + O2

Question 39

A 1.900 g sample of C6H12 is burned in an excess of oxygen. What mass of CO2 and H2O should be obtained?

A) 0.994 g CO2, 0.407 g H2O
B) 2.98 g CO2, 1.22 g H2O
C) 5.96 g CO2, 2.44 g H2O
D) 10.45 g CO2, 4.27 g G H2O
E) 5.23 g CO2, 2.38 g H2O

Question 40

Potassium superoxide (KO2) can simulate a plant-type action by consuming carbon dioxide (CO2) gas and releasing oxygen (O2) gas. The other product is potassium carbonate (K2CO3). When the equation for this process is balanced, it shows that:

A) 3 mol oxygen is produced per mol KO2 consumed
B) 2 mol KO2 is consumed per mol carbon dioxide
C) moles of reactants equals moles of product
D) 3 g of oxygen is produced per 2 g CO2 consumed
E) moles of products exceed moles of reactants

Question 41

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? H2(g) + O2(g) → H2O(l)

A) 4
B) 5
C) 8
D) 9
E) 7

Question 42

How many grams of a solid mixture containing strontium chloride would one need to make 558 mL of a 0.100 M strontium chloride solution, if the solid mixture contains 58.6% strontium chloride by weight?

A) 6.62 g
B) 15.1 g
C) 8.85 g
D) 5.19 g
E) 9.52 g

Question 43

Cryolite is a compound needed for the Hall-Heroult process for producing aluminum. Cryolite is produced by the following reaction: 6 HF + Al(OH)3 + 3 NaOH → Na3AlF6 + 6 H2O
How many grams of cryolite are produced if the reaction has a 94.3% yield and a limiting reagent of 27.8 grams of HF?

A) 275 g
B) 48.6 g
C) 45.9 g
D) 15.0 g
E) 15.9 g

Question 44

Given the reaction: P4(l) + 6 Cl2(g) → 4 PCl3(l)
If the percent yield is 82%, what mass of P4 is required to obtain 2.30 g PCl3 (Cl2 in excess)?

A) 0.63 g
B) 0.52 g
C) 0.43 g
D) 0.16 g
E) 0.95 g

Question 45

How many grams of ZnSO4 will be made from 41.0 grams each of Zn, K2Cr2O7, and H2SO4? 4 Zn + K2Cr2O7 + 7 H2SO4 → 4 ZnSO4 + 2 CrSO4 + K2SO4 + 7 H2O

A) 67.6 g
B) 38.6 g
C) 101 g
D) 20.6 g
E) 82.5 g

Question 46

Consider the gaseous reaction: N2H4(g) + 3 O2(g) → 2 NO2(g) + 2 H2O(g)
If the above reaction has a percent yield of 98.5%, what mass in grams of oxygen is needed to produce 49.0 g of NO2(g), assuming an excess of N2H4?

A) 50.4 g
B) 51.9 g
C) 25.9 g
D) 23.1 g
E) 11.5 g

Question 47

The Haber Process for the production of ammonia is represented by: 3 H2(g) + N2(g) → 2 NH3(g)
If a mixture of 30 g of hydrogen with 10 g of nitrogen produced 8.4 g of ammonia, what was the percent yield?

A) 84%
B) 69%
C) 49%
D) 28%
E) 20%

Question 48

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? C2H6 + O2 → CO2 + H2O

A) 5
B) 10
C) 19
D) 21
E) 25

Question 49

42.6 g Cu are combined with 84.0 g of HNO3 according to the reaction: 3 Cu + 8 HNO3 → 3 Cu(NO3)2 + 2 NO + 4 H2O.
Which reagent is limiting and how many grams of Cu(NO3)2 are produced?

A) Cu, 93.8 g
B) HNO3, 93.8 g
C) Cu, 125.6 g
D) HNO3, 125.6 g
E) Cu(NO3)2, 125.6 g

Question 50

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al(s) + HCl(aq) → AlCl3(aq) + H2(g)

A) 13
B) 11
C) 18
D) 19
E) 21

Question 51

If 0.500 mol of CaCl2 is mixed with 0.200 mol Na3PO4, the maximum amount in moles of Ca3(PO4)2 that can be formed is:

A) 0.17
B) 0.20
C) 0.10
D) 0.67
E) 0.50

Question 52

Given the reaction: 2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O,
How many moles of K2SO4 are produced by allowing five moles each of KMnO4, KI, and H2SO4 to react?

A) 3 mol
B) 1 mol
C) 2 mol
D) 4 mol
E) 5 mol

Question 53

One source of iodine is sodium iodate. Iodine is produced by a series of reactions. The first reaction is a reduction reaction with sodium hydrogen sulfite. IO3-( aq) + 3 HSO3- (aq) → I- (aq) + 3 SO42- (aq) + 3 H+(aq)
5 I- (aq) + IO3- (aq) + 6 H+ (aq) → 3 I2(s) + 3 H2O
How many grams of iodine are produced from 1.00 × 102 grams of NaHSO3 if each reaction has a 95.0% yield?

A) 48.8 g
B) 51.4 g
C) 185 g
D) 46.3 g
E) 44.0 g

Question 54

Given the following reactions: Fe + Br2 → FeBr2
3 FeBr2 + Br2 → Fe3Br8
If each reaction is 82.0% efficient, what mass of iron is necessary to make 8.45 g of Fe3Br8?

A) 0.870 g
B) 3.73 g
C) 2.14 g
D) 1.75 g
E) 2.61 g

Question 55

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CaC2(s) + H2O(l) → Ca(OH)2(s) + C2H2(g)

A) 8
B) 4
C) 5
D) 10
E) 9

Question 56

How many grams of CrSO4 will be made from 25.0 grams each of Zn, K2Cr2O7, and H2SO4? 4 Zn + K2Cr2O7 + 7 H2SO4 → 4 ZnSO4 + 2 CrSO4 + K2SO4 + 7 H2O

A) 10.8 g
B) 28.3 g
C) 25.2 g
D) 12.6 g
E) 37.8 g

Question 57

If 8.52 g each of zinc, potassium dichromate, and sulfuric acid are reacted by the reaction: 4 Zn + K2Cr2O7 + 7 H2SO4→ 4 ZnSO4 + 2 CrSO4 +K2SO4 + 7 H2O
How many grams of potassium dichromate will be left unreacted?

A) 1.05 g
B) 2.84 g
C) 7.30 g
D) 4.87 g
E) 3.65 g

Question 58

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? KClO3(s) → KCl(s) + O2(g)

A) 11
B) 10
C) 5
D) 7
E) 6

Question 59

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? Al + Fe2O3 → Al2O3 + Fe

A) 4
B) 6
C) 12
D) 9
E) 8

Question 60

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? PCl3(l) + Cl2(g) + P4O10(s) → POCl3(l)

A) 3
B) 18
C) 45
D) 10
E) 23

Question 61

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO2(s) +2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l)
Which is the limiting reagent and the amount of PbSO4 produced if 53.0 g of Pb, 77.3 g of PbO2, and 534 mL of 0.544 M solution of H2SO4 is used?

A) PbO2, 196 g
B) Pb, 77.6 g
C) Pb, 155 g
D) H2SO4, 88.1 g
E) H2SO4, 176 g

Question 62

What is the molarity of methanol, CH3OH (d = 0792 g/mL), if 150.0 mL is dissolved in enough water to make 4.00 L of solution?

A) 3.71 M
B) 1.17 M
C) 1.48 M
D) 0.927 M
E) 0.734 M

Question 63

What is the molarity of a sucrose solution (C12H22O11) if 110.0 g of a 92.0% pure solid is dissolved per 250.0 mL of water?

A) 0.296 M
B) 1.29 M
C) 0.321 M
D) 1.40 M
E) 1.18 M

Question 64

"Washing soda" (sodium carbonate) may be used to "soften" water by the removal of certain ions that would otherwise react with common soaps. When the "hardness" is due to calcium ion, the "softening" process may be represented as: Ca2+(aq) + CO32-(aq) → CaCO3(s)
What mass of sodium carbonate would be required to remove essentially all of the calcium ion from 750 L of solution containing 43 mg Ca2+ per liter?

A) 85 g
B) 67 g
C) 12 g
D) 48 g
E) 22 g

Question 65

What mass of oxygen gas would be consumed by the complete combustion of 7.5 g of a mixture of propane (C3H8) and butane (C4H10) in the mole ratio of C3H8/C4H10 = 1.33?

A) 3.9 g
B) 11 g
C) 14 g
D) 21 g
E) 27 g

Question 66

What is the molarity of formaldehyde in a solution containing 0.25 g of formaldehyde (CH2O) per mL?

A) 2.5 M
B) 25 M
C) 8.3 M
D) 83 M
E) 4.0 M

Question 67

What is the sum of the coefficients when the following is balanced with the smallest integer coefficients? CH3OH → CO + H2

A) 3
B) 8
C) 5
D) 4
E) 7

Question 68

How much Cl2, in g, is required to produce 12.0 g CCl4 according to the following reaction? CH4 + 4 Cl2 → CCl4 + 4 HCl

A) 12.0 g
B) 5.52 g
C) 22.1 g
D) 1.38 g
E) 11.0 g

Question 69

You have 10.00 L of a 0.350 M KCl solution, but you need a solution that is 0.450 M. What volume of water, in L, would you evaporate from the solution?

A) 4.38 L
B) 3.50 L
C) 2.85 L
D) 7.77 L
E) 2.22 L

Question 70

What mass of water is produced in the metathesis reaction 75.2 g Zn(OH)2 with 43.4 g HCl?

A) 13.6 g
B) 27.3 g
C) 10.7 g
D) 21.4 g
E) 31.8 g

Question 71

What is the sum of the coefficients when the following equation is balanced with the smallest integer coefficients? H2SO3 + Al(OH)3 → Al2(SO3)3 + H2O

A) 4
B) 5
C) 11
D) 12
E) 14

Question 72

The molarity of a solution that contains 14.7 g of H2SO4 in 200.0 mL solution is ________.

A) 1.5 M
B) 0.75 M
C) 0.77 M
D) 7.4 M
E) 3.0 M

Question 73

The chemical reaction during low current discharge of a simple "dry cell" involves: (unbalanced) Zn + MnO2 + NH4Cl → ZnCl2 + Mn2O3 + NH3 + H2O
What is the coefficient for zinc in the balanced equation that uses the lowest whole number ratios, and what is the limiting reagent for a process in which equal masses of reactants are mixed?

A) 1/Zn
B) 2/Zn
C) 1/MnO2
D) 2/MnO2
E) 2/NH4Cl

Question 74

The chemical reaction occurring during the discharge of a lead storage battery can be represented by the equation: Pb(s) + PbO2(s) + 2 H2SO4(aq) → 2 PbSO4(s) + 2 H2O(l) What mass of lead sulfate would result from the complete reaction of 41.4 g of lead?

A) 57.6 g
B) 60.5 g
C) 105 g
D) 115 g
E) 121 g

Question 75

If an aqueous solution containing 46 g of sodium carbonate per liter is mixed with an equal volume of 0.20 M aqueous hydrochloric acid, what would be the molarity of sodium chloride in the final solution, assuming volumes were additive?

A) 0.10 M
B) 0.20 M
C) 0.22 M
D) 0.43 M
E) 0.50 M

Question 76

Write the complete balanced equation for the complete combustion reaction expected to occur between C3H7OH and O2.

A) C3H7OH + O2 → 3 CO2 + 4 H2O
B) 2 C3H7OH + 9 CO2 → 6 CO2 + 8 H2O + 9 C
C) 2 C3H7OH + 6 CO2 → CO + 8 H2O
D) 2 C3H7OH + 9 O2 → 6 CO2 + 8 H2O
E) 2 C3H7OH + 9 O2 → 6 C + 8 H2 + 10 O2

Question 77

Our task is to measure the volume of blood in an elephant. One way to do this would be to drain its blood into a suitable container. Aside from harmful side effects which this method has on the elephant, it will not be successful, as blood will still remain behind in the tissues. Hence, we will inject 2.00 ml of a 2.00 M solution of a dye which the elephant will not appreciably metabolize or excrete in one hour and then measure the concentration of this dye in the bloodstream (our sample being taken from another leg than the point of injection) after 30 minutes, a sufficient time to thoroughly mix the dye in the bloodstream. The concentration of dye at this point is 1.25 x 10-5 M. What is the volume of blood in the elephant?

A) 320. L
B) 320000 L
C) 3.2 L
D) 80 L
E) 800 L

Question 78

Given the reaction: 2 KMnO4 + 10 KI + 8 H2SO4 → 6 K2SO4 + 2 MnSO4 + 5 I2 + 8 H2O
How many moles of I2 are produced by reacting 28.0 g KMnO4, 18.0 g KI, and 46.0 g H2SO4?

A) 0.108 mol
B) 0.0542 mol
C) 0.293 mol
D) 0.443 mol
E) 0.886 mol

Question 79

What mass of MgCl2 in grams must be added to 250.0 mL of a 0.25 M MgCl2 solution to produce a 0.40 M solution, assuming no change of volume upon addition?

A) 9.5 g
B) 6.0 g
C) 2.2 g
D) 3.6 g
E) 19 g

Question 80

To measure the volume of an irregularly shaped container filled with water, 1.00 mL of 2.00 M potassium chloride solution is added. After stirring, a 5.00 mL sample was found to contain 2.54 × 10-2 mg of potassium ion. What is the volume of the container?

A) 15.4 L
B) 29.4 L
C) 2.94 × 104 L
D) 3.97 × 10-4 L
E) 2.54 L