Deck 9: Stoichiometry and the Mole

Question 1

Alkynes have the general molecular formula CnH₂n_-2. Thus, when n = 2, the alkyne is C₂H₂ etc. If an alkyne has a molecular mass between 75 and 85, this alkyne is ________.

A) C₆H₁₀
B) C₆H₁₂
C) C₅H₁₆
D) C7H₁₂

Answer 1

C₆H₁₀

Question 2

The molar mass of a compound XClO₃ is 106.5. The molar mass (rounded to the nearest whole number) of X is ________, which is ________.

A) 39; K
B) 23; Na
C) 7; Li
D) 1; H

Answer 2

23; Na

Question 3

Alkenes have the general molecular formula CnH₂n. Thus, when n = 2, the alkene is C₂H₄. If an alkene has a molecular mass between 65 and 75, this alkene is ________.

A) C₅H₁₂
B) C₅H₁₀
C) C₆H₃
D) C₆H₁₂

Answer 3

C₅H₁₀

Question 4

The molar mass of a compound Ca(MO₃)₂ is 160. The atomic mass of M is ________, which is ________.

A) 12; C
B) 14; N
C) 32; S
D) 35; Cl

Question 5

The molecular mass of a compound X(NO₃)₃ is 213. The atomic mass of X is ________, which is ________.

A) 27; Al
B) 51; V
C) 56; Fe
D) 59; Co

Question 6

Which of the following has the greatest number of atoms?

A) (NH₄)₃PO₄
B) Na₂P₂O₃
C) (NH₄)₂Cr₂O₇
D) K₄Fe(CNO)₆

Question 7

Which of the following has the least number of atoms?

A) (NH₄)₃PO₄
B) Na₂P₂O₃
C) (NH₄)₂Cr₂O₇
D) K₄Fe(CNO)₆

Question 8

What is the mass in grams of 1.000 mole of P₂O₅?

A) 239.03 g
B) 61.96 g
C) 142.0 g
D) 46.98 g

Question 9

Which of the following quantities does not share the same molar mass as the others when rounded to the nearest whole number?

A) AL₂(SO₄)₃
B) C₁₂H₂₂O₁₁
C) C₂₄H₃₈O
D) Pb₃(PO₄)₄

Question 10

What is the mass in grams of 1.000 mole of a compound whose formula is C₃H₇O₂?

A) 29.14 g
B) 68.22 g
C) 37.54 g
D) 75.09 g

Question 11

The molar mass of a compound X(HCO₃)₂ is 146. The atomic weight of X when rounded to the nearest whole number is ________, which is ________.

A) 24; Mg
B) 40; Ca
C) 51; V
D) 56; Fe

Question 12

Which of the following has a molar mass equal to 133?

A) (NH₄)₃PO₃
B) Ca₃(PO₄)₂
C) AL₂(SO₃)₃
D) CO₂(CO₃)₂

Question 13

Which of the following has the highest molar mass?

A) (NH₄)₃PO₃
B) Ca₃(PO₄)₂
C) AL₂(SO₃)₃
D) CO₂(CO₃)₂

Question 14

The correct sequence of decreasing number of atoms per formula unit in the following is ________.

A) (NH₄)₃PO₄ > Na₂P₂O₃ > Na₃PO₄
B) Na₃PO₄ > (NH₄)₃PO₄ > Na₂P₂O₃
C) Na₂P₂O₃ > Na3PO₄ > (NH₄)₃PO₄
D) (NH₄)₃PO₄ > Na₃PO₄ > Na₂P₂O₃

Question 15

The number of oxygen atoms in 1 mole of AL₂(SO₄)₃ is ________.

A) 3
B) 4
C) 12
D) none of the above

Question 16

Which of the following pairs does not share the same molecular mass when rounded to the nearest whole number?

A) CH₃OH and oxygen gas
B) CO and nitrogen gas
C) C₂H₆O and C₂H₄O₂
D) C₄H₁₀O and C₃H₆O₂

Question 17

The molar mass for Pb(CO₃)₄ is ________.

A) 447
B) 409
C) 327
D) 303

Question 18

The molar mass of Ca₃(PO₄)₂ is ________.

A) 310
B) 279
C) 246
D) 215

Question 19

Alkanes have the general molecular formula CnH₂n+2. Thus, when n = 1, the alkane is CH₄, when n = 2, the alkane is C₂H₆ etc. If an alkane has a molar mass between 140 and 150, this alkane is ________.

A) C₉H₂₀
B) C12H₂₆
C) C₁₀H₂₂
D) C11H₂₄

Question 20

The molar mass of a compound AL₂(XO₄)₃ is 342. The atomic mass of X is ________, which is ________.

A) 31; P
B) 32; S
C) 52; Cr
D) 55; Mn

Question 21

A sample of methane gas that contains Avogadro's number of molecules has a mass of ________.

A) 8.0 g
B) 16.0 g
C) 32.0 g
D) 64.0 g

Question 22

16 g of oxygen gas is equal to ________.

A) the mass of one atom
B) the mass of one molecule
C) the mass of one mole
D) the mass of half a mole

Question 23

A sample of oxygen gas that contains twice Avogadro's number of molecules has a mass of ________.

A) 8.0 g
B) 16.0 g
C) 32.0 g
D) 64.0 g

Question 24

12 g of carbon is equal to ________.

A) the mass of one atom
B) the mass of one molecule
C) the mass of one mole
D) the mass of half a mole

Question 25

0.02 moles of a certain aluminum compound has a mass of 1.56 g. This compound may be ________.

A) aluminum hydroxide
B) aluminum nitrate
C) aluminum cyanide
D) aluminum permanganate

Question 26

A sample of calcium that contains Avogadro's number of atoms has a mass of ________.

A) 20 g
B) 40 g
C) 80 g
D) 160 g

Question 27

Which of the following contains the least number of atoms?

A) 1.0 mole C₆H₁₄
B) 3.0 moles N₂O₅
C) 12.0 moles silver
D) 3.0 moles water

Question 28

Which of the following does not have the same number atoms as the other three choices?

A) three moles Na₂SO₃
B) six moles of water
C) nine moles NaCl
D) five moles CH₄

Question 29

A sample of methane gas that contains Avogadro's number of atoms has a mass of ________.

A) 3.2 g
B) 6.4 g
C) 16.0 g
D) 80.0 g

Question 30

A sample of calcium that contains twice Avogadro's number of atoms has a mass of ________.

A) 20 g
B) 40 g
C) 80 g
D) 160 g

Question 31

0.3 moles of a certain calcium compound weigh 93 g. This compound may be ________.

A) calcium nitrate
B) calcium chromate
C) calcium phosphate
D) calcium sulfate

Question 32

What is the molar mass of a compound X if 0.0400 moles weigh 21.6 g?

A) 540
B) 185
C) 216
D) 864

Question 33

0.05 moles of a certain compound has a mass of 17.1 g. This compound may be ________.

A) aluminum sulfate
B) lead (II) chloride
C) cobalt (III) oxide
D) magnesium carbonate

Question 34

What is the mass of 0.0500 moles aluminum sulfate?

A) 6.15 g
B) 10.95 g
C) 17.1 g
D) 19.8 g

Question 35

A sample of oxygen gas that contains Avogadro's number of atoms has a mass of ________.

A) 8.0 g
B) 16.0 g
C) 32.0 g
D) 64.0 g

Question 36

A sample of oxygen gas that contains one-half of Avogadro's number of molecules has a mass of ________.

A) 8.0 g
B) 16.0 g
C) 32.0 g
D) 64.0 g

Question 37

Which of the following contains the greatest number of atoms?

A) 1.0 mole C₆H₁₄
B) 3.0 moles N₂O₅
C) 12.0 moles silver
D) 3.0 moles water

Question 38

A sample of calcium that contains four times Avogadro's number of atoms has a mass of ________.

A) 20 g
B) 40 g
C) 80 g
D) 160 g

Question 39

A sample of oxygen gas that contains Avogadro's number of molecules has a mass of ________.

A) 8.0 g
B) 16.0 g
C) 32.0 g
D) 64.0 g

Question 40

A sample of calcium that contains one-half Avogadro's number of atoms has a mass of ________.

A) 20 g
B) 40 g
C) 80 g
D) 160 g

Question 41

The number of oxygen atoms present in 32.4 g of N₂O₅ is ________.

A) 5.00
B) 9.03 × 10²³
C) 4.51 × 10²³
D) 1.81 × 10²³

Question 42

Which is the correct statement about one mole of ammonia, NH₃?

A) It contains 14 g nitrogen and 3 g hydrogen.
B) It contains 6.02 × 10²³ molecules.
C) It contains 1.8 × 10²⁴ atoms of hydrogen.
D) all of the above

Question 43

The number of atoms in 2.4 g of magnesium metal is ________.

A) 6.0 × 10²²
B) 3.7 × 10²²
C) 2.5 × 10²²
D) 1.7 × 10²²

Question 44

One molecule of water contains ________.

A) one mole of hydrogen
B) one mole of oxygen
C) one atom of oxygen
D) 16 g of oxygen

Question 45

Which of the following has 14 atoms per formula unit?

A) (NH₄)₂SO₃
B) Al(ClO₄)₃
C) Pb(CrO₄)₂
D) Mg₃(PO₄)₂

Question 46

A certain food contains 60 mg of table salt. This is approximately equal to ________ formula units.

A) 6 × 10²³
B) 6 × 10²²
C) 6 × 10²⁰
D) 6 × 10²⁶

Question 47

What is the mass of hydrogen that will react with 0.203 g of Li to form LiH?

A) 0.015 g
B) 0.030 g
C) 0.060 g
D) 0.120 g

Question 48

The total number of atoms in two moles SO₃ is ________.

A) 4
B) 8
C) 1.2 × 10²⁴
D) 4.8 × 10²⁴

Question 49

Which has more ions-2.0 moles of AL₂(SO₄)₃ or 3.0 moles of Na₃PO₄?

A) 2.0 moles of AL₂(SO₄)₃
B) 3.0 moles of Na3PO₄
C) There are equal number of ions in both ionic compounds.
D) It cannot be determined based on the information given.

Question 50

What is the mass of sulfur that will react with 0.527 g of copper metal to yield copper (I) sulfide?

A) 0.066 g
B) 0.132 g
C) 0.264 g
D) 0.198 g

Question 51

The ingredients to make 50 servings of fruit punch are: ∙ 2-1/2 cups white sugar
∙ 6 cups water
∙ 2 (3-ounce) packages strawberry flavored gelatin mix
∙ 1 (46-fluid-ounce) can pineapple juice
∙ 2/3 cup lemon juice
∙ 1 quart orange juice
∙ 2 (2-liter) bottles lemon-lime flavored carbonated beverage
How many servings of punch can you make using the above recipe, if you have 2 gallons of pineapple juice, 8 (2-liter) bottles of lemon-lime flavored soda and 2 gallons of orange juice? Assume you have plenty of all the other ingredients.

A) 125 servings
B) 200 servings
C) 278 servings
D) 375 servings
E) 400 servings

Question 52

Which of the following does not contain 3.0 × 10²⁴ atoms?

A) 60 g of carbon
B) one mole of methane
C) two moles of water
D) 160 g sulfur

Question 53

0.011 moles of an element has a mass of 2.56 g. This element is ________.

A) Pb
B) V
C) Ac
D) Th

Question 54

The mass of oxygen present in 11.7 g of AL₂(CO₃)₃ is ________.

A) 7.20 g
B) 14.4 g
C) 8.10 g
D) 4.05 g

Question 55

Which of the following will not have the same number atoms as the other three choices?

A) K₂Cr₂O₇
B) (NH₄)₂S
C) Al(ClO₂)₃
D) Ba(HCO₃)₂

Question 56

The mass of CaCL₂ that contains 17.8 g of chlorine is ________.

A) 35.6 g
B) 53.4 g
C) 27.9 g
D) 20.5 g

Question 57

Which contains more carbon?

A) 24 g methane
B) 140 g sodium carbonate
C) 40 g carbon monoxide
D) 15 g octane, C₈H₁₈

Question 58

The number of moles of chlorine atoms in 12.5 g of carbon tetrachloride is ________.

A) 0.081
B) 0.162
C) 0.325
D) 0.648

Question 59

The mass of one formula unit of AL₂(SO₄)₃ is ________ g.

A) 342
B) 0.0029
C) 5.7 × 10^-22
D) 8.0 × 10^-27

Question 60

The number of phosphorus atoms in one molecule of H₃PO₄ is ________.

A) 1
B) 8
C) 6.02 × 10²³
D) 4.8 × 10²³

Question 61

The balanced equation involves the corresponding coefficients ________. C₂H₆O + O₂ → CO₂ + H₂O

A) 1: 2: 2: 3
B) 1: 3: 2: 3
C) 2: 7: 4: 6
D) 2: 9: 4: 6

Question 62

The maximum number of moles of carbon dioxide that can be produced from four moles of C₃H₈O is ________. 2 C₃H₈O + 9 O₂ → 6 CO₂ + 8 H₂O

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

Question 63

If 4 moles of nitrogen produces 2 moles of nitrogen dioxide, then the percent yield is ________. N₂ + 2 O₂ → 2 NO₂

A) 100%
B) 50%
C) 25%
D) 12.5%

Question 64

What is the theoretical mass of carbon dioxide produced from 4.0 moles of NaHCO₃? NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

A) 1.0 g
B) 22 g
C) 44 g
D) 88 g

Question 65

The theoretical number of carbon dioxide moles produced from 6 moles of NaHCO₃ is ________.' NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

A) 1
B) 3
C) 6
D) 12

Question 66

The balanced equation involves the corresponding coefficients ________. NaN₃ → Na + N₂

A) 2: 2: 3
B) 1: 2: 3
C) 2: 1: 3
D) 3: 3: 2

Question 67

Which reactant is present in excess if 10.0 g of CaO react with 3.0 mol of H₂O? CaO + H₂O → Ca(OH)₂

A) Ca(OH)2
B) CaO
C) H₂O
D) None of the above, the amounts exactly balance.

Question 68

The balanced equation involves the corresponding coefficients ________. NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

A) 1: 1: 1: 1
B) 1: 2: 1: 1
C) 2: 1: 1: 1
D) 2: 1: 2: 1

Question 69

Which of the following abides by the principle of mass conservation according to the balanced reaction? 4 K + O₂ → 2 K₂O

A) 39.0g K + 16.0g O₂ → 94.0g K₂O
B) 156.0 g K + 24.0g O₂ → 188.0g K₂O
C) 156.0g K + 32.0g O₂ → 188.0g K₂O
D) 78.0g K + 32.0g O₂ → 110.0g K₂O

Question 70

The balanced equation involves the corresponding coefficients ________. NH₃ + O₂ → NO + H₂O

A) 2: 3: 2: 3
B) 2: 5: 2: 3
C) 4: 5: 4: 6
D) 2: 2: 3: 3

Question 71

The balanced equation involves the corresponding coefficients ________. C₆H₁₄ + O₂ → CO₂ + H₂O

A) 1: 9: 6: 7
B) 1: 10: 6: 7
C) 2: 19: 12:14
D) 2: 21: 6: 7

Question 72

What is the percent yield for a given process, if 4.0 kg of a product is recovered from a reaction whose theoretical yield is 5.6 kg?

A) 41%
B) 62%
C) 71%
D) 89%

Question 73

If 5.0 moles of ammonia is produced, then the number of hydrogen molecules consumed is ________. N₂ + 3 H₂ → 2 NH₃

A) 5.0
B) 7.5
C) 3.2
D) 1.0

Question 74

The theoretical number of carbon dioxide moles produced from 3 moles of C₂H₆O is ________. C₂H₆O + O₂ → CO₂ + H₂O

A) 3
B) 4
C) 6
D) 9

Question 75

If 14 kg of nitrogen yields 23 kg of nitrogen dioxide, then the percent yield for the reaction is ________. N₂ + 2 O₂ → 2 NO₂

A) 100%
B) 50%
C) 25%
D) 12%

Question 76

The maximum number of moles of water that can be produced from 0.5 moles of C₃H₈O is ________. 2 C₃H₈O + 9 O₂ → 6 CO₂ + 8 H₂O

A) 0.5
B) 2
C) 4
D) 8

Question 77

0.842 g chlorine will combine with ________ g of sulfur to produce SCL₂.

A) 0.481
B) 1.870
C) 0.305
D) 0.379

Question 78

The balanced equation involves the corresponding coefficients ________. H₂SO₄ + Cu → SO₂ + H₂O + CuSO₄

A) 2: 1: 1: 2: 1
B) 1: 1: 2: 2: 1
C) 2: 1: 2: 1: 1
D) 2: 1: 1: 2: 2

Question 79

The theoretical number of moles of water produced from 8 moles of NaHCO₃ is ________. NaHCO₃ → Na₂CO₃ + CO₂ + H₂O

A) 2
B) 4
C) 8
D) 16

Question 80

Two moles of hydrogen react with excess nitrogen to produce ________ moles of ammonia.. N₂ + 3 H₂ → 2 NH₃

A) 1.3
B) 2.0
C) 1.0
D) 6.0