Download Stoichiometry Regents Unit Review

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Stoichiometry Regents Unit Review
Part I:
1. Which formula correctly represents the composition of iron (III) oxide?
(1) FeO3 (2) Fe2O3 (3) Fe3O (4) Fe3O2
2. In which substance does chlorine have an oxidation number of +1?
(1) Cl2 (2) HCl (3) HClO (4) HClO2
3. What is the correct IUPAC name for the compound NH4Cl?
(1) nitrogen chloride (2) nitrogen chlorate (3) ammonium chloride (4) ammonium chlorate
4. What is the correct formula for iron (III) phosphate?
(1) FeP (3) FePO4 (2) Fe3P2 (4) Fe 3(PO4)2
5. Write an IUPAC name for the compound N2O5.
6. Which substance has a chemical formula with the same ratio of metal ions to nonmetal ions as in potassium
sulfide?
(1) sodium oxide (2) sodium chloride (3) magnesium oxide (4) magnesium chloride
7. What is the chemical formula for sodium sulfate?
(1) Na2SO3
(2) Na2SO4
(3) NaSO3
(4) NaSO4
8. What is the IUPAC name for the compound FeS?
(1) iron(II) sulfate
(2) iron(III) sulfate
(3) iron(II) sulfide
(4) iron(III) sulfide
9. A compound is made up of iron and oxygen, only. The ratio of iron ions to oxide ions is 2:3 in this
compound. The IUPAC name for this compound is
(1) triiron dioxide
(2) iron(II) oxide
(3) iron(III) oxide
(4) iron trioxide
Part II:
1. The gram formula mass of NH4Cl is
(1) 22.4 g/mole
(2) 28.0 g/mole
(3) 53.5 g/mole
(4) 95.5 g/mole
2. What is the total number of oxygen atoms in the formula MgSO4•7H2O?
(The • represents seven units of H2O attached to one unit of MgSO4)
(1) 11
(2) 7 (3) 5
(4) 4
adapted from http://www.chemcool.com
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3. A compound has a gram formula mass of 56 grams per mole. What is the molecular formula for this
compound?
(1) CH2
(2) C2H4
(3) C3H6
(4) C4H8
4. The empirical formula of a compound is CH2 . Which molecular formula is correctly paired with a structural
formula for this compound?
5. Which is an empirical formula?
(1) P2O5 (2) P4O6 (3) C2H4 (4) C3H6
6. What is the molecular formula of a compound that has a molecular mass of 54 and the empirical formula
C 2H 3?
(1) C2H3 (3) C6H9 (2) C4H6 (4) C8H12
7. What is the empirical formula of a compound with the molecular formula N2O4 ?
(1) NO (2) NO2 (3) N2O (4) N2O3
8. The empirical formula for naphthalene is C5H4 and the molecular mass of naphthalene is 128 grams/mole.
What is the molecular formula for naphthalene?
9. What is the empirical formula for the compound C6H12O6 ?
(1) CH2O (2) C2H4O2 (3) C3H6O3 (4) C6H12O6
10. Which pair of formulas correctly represents a molecular formula and its corresponding empirical formula?
(1) C2H2 and CH (2) C3H4 and CH2 (3) C4H6 and CH (4) C5H8 and C2H2
11. Which pair of compounds has the same empirical formula?
(1) C2H2 and C6H6 (2) C2H6 and C3H8 (3) CH3OH and C2H5OH (4) CH3CHO and CH3COOH
12. The molecular formula of glucose is C6H12O6. What is the empirical formula of glucose?
(1) CHO
(2) CH2O
adapted from http://www.chemcool.com
(3) C6H12O6
(4) C12H24O12
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13. Given the structural formula:
What is the empirical formula of this compound?
(1) CH3O
(2) C2H5O
(3) C4H10O2
14. Given the balanced equation:
(4) C8H20O4
2C + 3H2 → C2H6
What is the total number of moles of C that must completely react to produce 2.0 moles of C2H6?
(1) 1.0 mol
(2) 2.0 mol
(3) 3.0 mol
(4) 4.0 mol
15. What is the total number of moles in 80.0 grams of C2H5Cl (gram-formula mass = 64.5 grams/mole)?
16. Given the balanced equation representing a reaction: F2(g) + H2(g) → 2HF(g) What is the mole ratio of
H2(g) to HF(g) in this reaction?
(1) 1:1 (2) 1:2 (3) 2:1(4) 2:3
17. A substance has an empirical formula of CH2 and a molar mass of 56 grams per mole. The molecular formula
for this compound is
(1) CH2 (2) C4H6 (3) C4H8 (4) C8H4
18. What is the mass of 4.76 moles of Na3PO4 (gram-formula mass = 164 grams/mole)?
Part III:
1. Given the reaction: 6CO2 + 6 H2O → C6H12O6 + 6 O2 What is the total number of moles of water needed
to make 2.5 moles of C6H12O6?
(1) 2.5 (2) 6.0 (3) 12 (4) 15
2. If an equation is balanced properly, both sides of the equation must have the same number of
(1) atoms (2) coefficients (3) molecules (4) moles of molecules
3. Given the unbalanced equation: ___ Al + ___ CuSO4 → ___ Al2(SO4)3 + ___ Cu
When the equation is balanced using the smallest whole-number coefficients, what is the coefficient of Al?
(1) 1 (2) 2 (3) 3 (4) 4
4. Given the equation: 2C2H2(g) + 5 O2(g) → 4 CO2(g) + 2 H2O(g) How many moles of oxygen are required to
react completely with 1.0 mole of C2H2?
(1) 2.5
(2) 2.0
(3) 5.0
adapted from http://www.chemcool.com
(4) 10
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5. Given the unbalanced equation: ___ Fe2O3 + ___ CO → ___ Fe + ___ CO2
When the equation is correctly balanced using the smallest whole-number coefficients, what is the coefficient of
CO?
(1) 1 (2) 2 (3) 3 (4) 4
6. Given the reaction: PbCl2(aq) + Na2CrO4(aq) → PbCrO4(S) + 2 NaCl(aq)
What is the total number of moles of NaCl formed when 2 moles of Na2CrO4 react completely?
(1) 1mole (2) 2 moles (3) 3 moles (4) 4 moles
7 What is conserved during a chemical reaction?
(1) mass, only (2) charge, only (3) both mass and charge (4) neither mass nor charge
8 Given the balanced equation: 2 C4H10 (g) + 13 O2 (g) → 8 CO2 (g) + 10 H2O(g) What is the total number of
moles of O2 (g) that must react completely with 5.00 moles of C4H10 (g)?
(1) 10.0 (3) 26.5 (2) 20.0 (4) 32.5
Base your answers to questions 9 and 10 on the information below.
Given the unbalanced equation:
enzyme
____ C6H12O6 →>>>> ____ C2H5OH + ____ CO2
9. Balance the equation using the lowest whole-number coefficients.
10. Identify the type of reaction represented.
Base your answers to questions 11 and 12 on the unbalanced equation provided below.
_____C5H12(g) + ______ O2(g) → ______ CO2(g) + ______ H2O(g)
11. Balance the equation using the smallest whole-number coefficients.
12. Using your balanced equation, show a correct numerical setup for calculating the total number of moles of
H2O(g) produced when 5.0 moles of O2(g) are completely consumed and record your answer.
13. Given the reaction: N2(g) + 3H2(g) 2NH3(g) What is the mole-to-mole ratio between nitrogen gas and
hydrogen gas?
(1) 1: 2 (3) 2: 2 (2) 1: 3 (4) 2: 3
14. All chemical reactions have a conservation of
(1) mass, only (2) mass and charge, only (3) charge and energy, only (4) mass, charge, and energy
15. Given the equation: 2H2(g) + O2(g) → 2 H2O(g)
If 8.0 moles of O2 are completely consumed, what is the total number of moles of H2O produced?
adapted from http://www.chemcool.com
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16. Show a correct numerical setup for calculating the number of moles of CO2 (gram-formula mass = 44
g/mol) present in 11 grams of CO2.
17. Which equation shows a conservation of mass?
(1) Na + Cl2 → NaCl
(3) H2O → H2 + O2
(2) Al + Br2 → AlBr3
(4) PCl5 → PCl3 + Cl2
18. Given the balanced equation: 4Al(s) + 3O2(g) -→ 2Al2O3(s)
What is the total number of moles of O2(g) that must react completely with 8.0 moles of Al(s) in order to form
Al2O3(s)?
19. Which chemical equation is correctly balanced?
(1) H2(g) + O2(g) → H2O(g)
(3) 2NaCl(s) → Na(s) + Cl2(g)
(2) N2(g) + H2(g) → NH3(g)
(4) 2KCl(s) → 2K(s) + Cl2(g)
Base your answers to questions 20 on the information below.
Air bags are an important safety feature in modern automobiles. An air bag is inflated in milliseconds by the
explosive decomposition of NaN3(s). The decomposition reaction produces N2(g), as well as Na(s), according to
the unbalanced equation below.
NaN3(s) → Na(s) + N2(g)
20. Balance the equation for the decomposition of NaN3, using the smallest whole-number coefficients.
21. Given the balanced equation: CaCO3(s) + 2HCl(aq) → CaCl2(aq) + H2O(l) + CO2(g)
What is the total number of moles of CO2 formed when 20. moles of HCl is completely consumed?
(1) 5.0 mol
(2) 10. mol
(3) 20. mol
(4) 40. mol
Part IV:
1. The percent by mass of hydrogen in NH3 is equal to
(1) 17/1 x 100
(2) 17/3 x 100
(3) 1/17 x 100
(4) 3/17 x 100
2. A hydrate is a compound that includes water molecules within its crystal structure. During an experiment to
determine the percent by mass of water in a hydrated crystal, a student found the mass of the hydrated crystal to
be 4.10 grams. After heating to constant mass, the mass was 3.70 grams. What is the percent by mass of water in
this crystal?
(1) 90.%
(2) 11%
(3) 9.8%
(4) 0.40%
3. What is the percent by mass of oxygen in H2SO4 ? [formula mass = 98g]
(1) 16%
(2) 33%
adapted from http://www.chemcool.com
(3) 65%
(4) 98%
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4. The percent by mass of calcium in the compound calcium sulfate (CaSO4) is approximately
(1) 15%
(2) 29%
(3) 34%
(4) 47%
5. In which compound is the percent by mass of oxygen greatest?
(1) BeO (2) MgO (3) CaO (4) SrO
Base your answers to questions 6 and 7 on the information below.
Gypsum is a mineral that is used in the construction industry to make drywall (sheetrock). The chemical formula
for this hydrated compound is CaSO4•2H2O. A hydrated compound contains water molecules within its
crystalline structure. Gypsum contains 2 moles of water for each 1 mole of calcium sulfate.
6. What is the gram formula mass of CaSO4•2H2O? ___________ g/mol
7. a. Show a correct numerical setup for calculating the percent composition by mass of water in this compound.
b. Record your answer. __________%
8. What is the percent by mass of oxygen in propanal, CH3CH2CHO?
(1) 10.0%
(2) 38.1%
(3) 27.6%
(4) 62.1%
9. What is the percent composition by mass of aluminum in Al2(SO4)3 (gram-formula mass = 342 grams/mole)?
(1) 7.89%
(2) 15.8%
(3) 20.8%
(4) 36.0%
10. Show a correct numerical setup for calculating the percent composition by mass of oxygen in NO2.
11. A sample of a substance containing only magnesium and chlorine was tested in the laboratory and was found
to be composed of 74.5% chlorine by mass. If the total mass of the sample was 190.2 grams, what was the mass
of the magnesium?
(1) 24.3 g
(2) 48.5 g
(3) 70.9 g
(4) 142 g
12. What is the percent composition by mass of nitrogen in NH4NO3 (gram-formula mass = 80.0 grams/mole)?
(1) 17.5%
(2) 35.0%
(3) 52.5%
(4) 60.0%
13. In which compound is the percent composition by mass of chlorine equal to 42%?
(1) HClO (gram-formula mass = 52 g/mol)
(2) HClO2 (gram-formula mass = 68 g/mol)
(3) HClO3 (gram-formula mass = 84 g/mol)
(4) HClO4 (gram-formula mass = 100. g/mol)
14. The percent composition by mass of magnesium in MgBr2 (gram-formula mass = 184 grams/mole) is equal
to
adapted from http://www.chemcool.com
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Part V:
1. Potassium chlorate aqueous reacts to yield potassium chloride aqueous and oxygen gas.
a. Write and balance the above chemical reaction.
b. State what type of simple chemical reaction the above reaction is.
2. Zinc metal reacts with silver nitrate aqueous to yield silver metal and zinc nitrate aqueous.
a. Write and balance the above chemical reaction.
b. State what type of simple chemical reaction the above reaction is.
3. Iron metal reacts with oxygen gas to yield solid iron (III) oxide.
a. Write and balance the above chemical reaction.
b. State what type of simple chemical reaction the above reaction is.
4. Calcium hydroxide aqueous reacts with hydrogen sulfate aqueous to yield liquid water and calcium sulfate
solid.
a. Write and balance the above chemical reaction.
b. State what type of simple chemical reaction the above reaction is.
5. Propane gas (C3H8) reacts with oxygen gas to yield carbon dioxide gas and liquid water.
a. Write and balance the above chemical reaction.
b. State what type of simple chemical reaction the above reaction is.
6. Which equation represents a double replacement reaction?
(1) 2 Na + 2 H2O → 2 NaOH + H2
(3) LiOH + HCl → LiCl + H2O
adapted from http://www.chemcool.com
(2) CaCO3 → CaO + CO2
(4) CH4 + 2 O2 → CO2 + 2 H2O
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7. Given the reaction: Mg(s) + 2 AgNO3 (aq) → Mg( NO3)2 (aq) + 2 Ag(s) Which type of reaction is
represented?
(1) single replacement (2) double replacement (3) synthesis (4) decomposition
Base your answers to questions 8 through 10 on the balanced chemical equation below.
2H2O → 2H2 + O2
8. What type of reaction does this equation represent?
9. How does the balanced chemical equation show the Law of Conservation of Mass?
10. What is the total number of moles of O2 produced when 8 moles of H2O is completely consumed?
11. Given the balanced equation: 2KClO3 → 2KCl + 3O2 Which type of reaction is represented by this
equation?
(1) synthesis
(2) decomposition
(3) single replacement
12. Given the incomplete equation for the combustion of ethane
What is the formula of the missing product?
(4) double replacement
2C2H6 + 7O2 → 4CO2 + 6 ____
(1) CH3OH (2) HCOOH (3) H2O (4) H2O2
13. Which list includes three types of chemical reactions?
(1) condensation, double replacement, and sublimation
(3) decomposition, double replacement, and synthesis
(2) condensation, solidification, and synthesis
(4) decomposition, solidification, and sublimation
Base your answers to questions 14 through 16 on the information below.
A student places a 2.50-gram sample of magnesium metal in a bottle and fits the bottle with a 2-hole stopper as
shown in the diagram. Hydrochloric acid is added to the bottle, causing a reaction. As the reaction proceeds,
hydrogen gas travels through the tubing to an
inverted bottle filled with water, displacing some of the water in the bottle.
14. Balance the equation for the reaction of magnesium and hydrochloric acid, using the smallest whole-number
coefficients.
adapted from http://www.chemcool.com
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15. Identify the type of chemical reaction that occurs when magnesium reacts with hydrochloric acid.
16. Show a correct numerical setup for calculating the number of moles of magnesium used in the experiment.
Part VI:
1. The reactants of a double replacement reaction are barium nitrate and sodium phosphate.
a) Find the 2 products and write a balanced chemical equation for the reaction.
b) Predict the solubility of all the compounds.
2. The reactants of a double replacement reaction are strontium chloride and potassium phosphate.
a) Find the 2 products and write a balanced chemical equation for the reaction.
b) Predict the solubility of all the compounds.
3. According to Table F, which of these salts is least soluble in water?
(1) LiCl
(2) RbCl (3) FeCl2 (4) PbCl2
4. Based on Reference Table F, which of these salts is the best electrolyte?
(1) sodium nitrate (2) magnesium carbonate (3) silver chloride (4) barium sulfate
5. Based on Reference Table F, which of these saturated solutions has the lowest concentration of dissolved
ions?
(1) NaCl(aq) (2) MgCl2(aq) (3) NiCl2(aq) (4) AgCl(aq)
6. According to Reference Table F, which of these compounds is the least soluble in water?
(1) K2CO3
(2) KC2H3O2
(3) Ca3(PO4)2
(4) Ca(NO3)2
7. Which ion, when combined with chloride ions, Cl–, forms an insoluble substance in water?
(1) Fe2+ (2) Mg2+ (3) Pb2+ (4) Zn2+
8. Which compound is insoluble in water?
(1) BaSO4
(2) CaCrO4
adapted from http://www.chemcool.com
(3) KClO3
(4) Na2S
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