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03 Chemical Reactions and Stoichiometry Online Quiz Questions

Use this free practice quiz with 20 questions to review 03 Chemical Reactions and Stoichiometry, test your knowledge, and prepare for your next test or exam.

20 questions
01
Choose one
1 point

Given CH4+2O2→CO2+2H2O\mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O}, which statement best classifies the reaction and describes its product pattern?

  1. A

    Combustion: a hydrocarbon reacts with oxygen and commonly forms carbon dioxide and water.

  2. B

    Decomposition: one compound breaks into simpler substances.

  3. C

    Single displacement: oxygen replaces hydrogen in methane.

  4. D

    Synthesis: two simpler substances combine to form one product.

02
Choose one
1 point

The balanced reaction 2H2O2→2H2O+O2\mathrm{2H_2O_2 \rightarrow 2H_2O + O_2} has one compound as its only reactant. Which reaction pattern does it show?

  1. A

    Synthesis, because two reactants combine to form one compound.

  2. B

    Decomposition, because one compound forms simpler products.

  3. C

    Double displacement, because two compounds exchange ions.

  4. D

    Combustion, because a hydrocarbon reacts with oxygen.

03
Choose one
1 point

Which condition identifies a reaction as oxidation–reduction (redox), rather than merely identifying a reaction by its products?

  1. A

    Ions exchange partners, with no change in oxidation states.

  2. B

    A solid forms from dissolved ions, which is the defining feature of every redox reaction.

  3. C

    Electrons are transferred and oxidation states change.

  4. D

    An acid and a base produce water, which is the defining feature of every redox reaction.

04
Choose one
1 point

Which option balances H2+O2→H2O\mathrm{H_2 + O_2 \rightarrow H_2O} while preserving the formulas and using the smallest whole-number coefficients?

  1. A

    H2+O2→H2O\mathrm{H_2 + O_2 \rightarrow H_2O}

  2. B

    H2+2O2→H2O\mathrm{H_2 + 2O_2 \rightarrow H_2O}

  3. C

    2H2+2O2→2H2O\mathrm{2H_2 + 2O_2 \rightarrow 2H_2O}

  4. D

    2H2+O2→2H2O\mathrm{2H_2 + O_2 \rightarrow 2H_2O}

05
Choose one
1 point

For 2Al+3Cl2→2AlCl3\mathrm{2Al + 3Cl_2 \rightarrow 2AlCl_3}, aluminum is in excess. How many moles of AlCl3\mathrm{AlCl_3} can form from 4.54.5 mol Cl2\mathrm{Cl_2}?

  1. A

    3.03.0 mol AlCl3\mathrm{AlCl_3}

  2. B

    4.54.5 mol AlCl3\mathrm{AlCl_3}

  3. C

    6.756.75 mol AlCl3\mathrm{AlCl_3}

  4. D

    9.09.0 mol AlCl3\mathrm{AlCl_3}

06
Choose one
1 point

For 2Al+3Cl2→2AlCl3\mathrm{2Al + 3Cl_2 \rightarrow 2AlCl_3}, chlorine is in excess. What mass of AlCl3\mathrm{AlCl_3} can form from 10.810.8 g Al? Use molar masses 27.027.0 g/mol for Al and 133.5133.5 g/mol for AlCl3\mathrm{AlCl_3}.

  1. A

    27.027.0 g AlCl3\mathrm{AlCl_3}

  2. B

    53.453.4 g AlCl3\mathrm{AlCl_3}

  3. C

    66.866.8 g AlCl3\mathrm{AlCl_3}

  4. D

    133.5133.5 g AlCl3\mathrm{AlCl_3}

07
Choose one
1 point

In AgNO3(aq)+NaCl(aq)→AgCl(s)+NaNO3(aq)\mathrm{AgNO_3(aq) + NaCl(aq) \rightarrow AgCl(s) + NaNO_3(aq)}, which classification is supported by both the reactant pattern and the product states?

  1. A

    Single displacement, because sodium replaces silver in a metal element.

  2. B

    Synthesis, because two dissolved compounds form one product.

  3. C

    Double displacement that forms a precipitate.

  4. D

    Combustion, because the reaction produces a solid.

08
Choose one
1 point

For 2H2+O2→2H2O\mathrm{2H_2 + O_2 \rightarrow 2H_2O}, a mixture contains 7.07.0 mol H2\mathrm{H_2} and 3.03.0 mol O2\mathrm{O_2}. Which reactant is limiting?

  1. A

    H2\mathrm{H_2} is limiting because its coefficient is larger.

  2. B

    H2\mathrm{H_2} is limiting because there are more moles of it.

  3. C

    Neither reactant is limiting because both are present in moles.

  4. D

    O2\mathrm{O_2} is limiting because 3.03.0 mol requires only 6.06.0 mol H2\mathrm{H_2}, less than the 7.07.0 mol available.

09
Choose one
1 point

A reaction has an actual yield of 3.603.60 g and a theoretical yield of 4.504.50 g. What is its percent yield?

  1. A

    80.0%80.0\%

  2. B

    125%125\%

  3. C

    0.800%0.800\%

  4. D

    4.00%4.00\%

10
Choose one
1 point

How many moles of dissolved substance are in 35.035.0 mL of a 0.1200.120 M solution? Use n=MVn=MV and convert the volume to liters.

  1. A

    0.0004200.000420 mol

  2. B

    0.004200.00420 mol

  3. C

    0.04200.0420 mol

  4. D

    4.204.20 mol

11
Choose one
1 point

What volume of 0.1000.100 M NaOH is needed to react completely with 18.018.0 mL of 0.2500.250 M H2SO4\mathrm{H_2SO_4}, according to H2SO4+2NaOH→Na2SO4+2H2O\mathrm{H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O}?

  1. A

    22.522.5 mL

  2. B

    45.045.0 mL

  3. C

    90.090.0 mL

  4. D

    180180 mL

12
Choose one
1 point

The reaction HCl+NaOH→NaCl+H2O\mathrm{HCl + NaOH \rightarrow NaCl + H_2O} has an acid and a base as reactants. Which classification best describes its characteristic reaction pattern?

  1. A

    Decomposition, because water is one of the products.

  2. B

    Combustion, because two reactants combine.

  3. C

    Single displacement, because sodium is present.

  4. D

    Acid–base neutralization, because an acid and a base produce a salt and water.

13
Choose one
1 point

Which equation for forming iron(III) oxide is balanced with the smallest whole-number coefficients?

  1. A

    2Fe+O2→Fe2O3\mathrm{2Fe + O_2 \rightarrow Fe_2O_3}

  2. B

    4Fe+3O2→2Fe2O3\mathrm{4Fe + 3O_2 \rightarrow 2Fe_2O_3}

  3. C

    3Fe+2O2→Fe2O3\mathrm{3Fe + 2O_2 \rightarrow Fe_2O_3}

  4. D

    2Fe+3O2→Fe2O3\mathrm{2Fe + 3O_2 \rightarrow Fe_2O_3}

14
Choose one
1 point

Which equation shows a double-displacement reaction?

  1. A

    2H2+O2→2H2O\mathrm{2H_2 + O_2 \rightarrow 2H_2O}

  2. B

    2H2O2→2H2O+O2\mathrm{2H_2O_2 \rightarrow 2H_2O + O_2}

  3. C

    AgNO3+NaCl→AgCl+NaNO3\mathrm{AgNO_3 + NaCl \rightarrow AgCl + NaNO_3}

  4. D

    CH4+2O2→CO2+2H2O\mathrm{CH_4 + 2O_2 \rightarrow CO_2 + 2H_2O}

15
Choose one
1 point

For Zn+2HCl→ZnCl2+H2\mathrm{Zn + 2HCl \rightarrow ZnCl_2 + H_2}, which classification correctly accounts for both the reaction pattern and electron transfer?

  1. A

    It is only a synthesis reaction; no electron transfer occurs.

  2. B

    It is both single displacement and redox.

  3. C

    It is only double displacement because two reactants form two products.

  4. D

    It is a decomposition reaction because hydrogen gas is formed.

16
Choose one
1 point

For N2+3H2→2NH3\mathrm{N_2 + 3H_2 \rightarrow 2NH_3}, nitrogen is in excess. How many moles of ammonia can form from 4.54.5 mol of hydrogen?

  1. A

    1.51.5 mol NH3\mathrm{NH_3}

  2. B

    2.02.0 mol NH3\mathrm{NH_3}

  3. C

    3.03.0 mol NH3\mathrm{NH_3}

  4. D

    6.756.75 mol NH3\mathrm{NH_3}

17
Choose one
1 point

For 2H2+O2→2H2O\mathrm{2H_2 + O_2 \rightarrow 2H_2O}, oxygen is in excess. If 8.0 g8.0\,\mathrm{g} of H2\mathrm{H_2} reacts, what mass of water forms? Use molar masses 2.0 g/mol2.0\,\mathrm{g/mol} for H2\mathrm{H_2} and 18.0 g/mol18.0\,\mathrm{g/mol} for H2O\mathrm{H_2O}.

  1. A

    18 g18\,\mathrm{g}

  2. B

    36 g36\,\mathrm{g}

  3. C

    64 g64\,\mathrm{g}

  4. D

    72 g72\,\mathrm{g}

18
Choose one
1 point

For 2CO+O2→2CO2\mathrm{2CO + O_2 \rightarrow 2CO_2}, a mixture contains 5.05.0 mol CO\mathrm{CO} and 2.02.0 mol O2\mathrm{O_2}. Which statement correctly identifies the limiting reactant, theoretical yield, and amount of excess reactant left?

  1. A

    CO\mathrm{CO} is limiting; 5.05.0 mol CO2\mathrm{CO_2} forms and no CO\mathrm{CO} remains.

  2. B

    O2\mathrm{O_2} is limiting; 5.05.0 mol CO2\mathrm{CO_2} forms and 1.01.0 mol O2\mathrm{O_2} remains.

  3. C

    O2\mathrm{O_2} is limiting; 4.04.0 mol CO2\mathrm{CO_2} forms and 1.01.0 mol CO\mathrm{CO} remains.

  4. D

    Neither reactant is limiting; 5.05.0 mol CO2\mathrm{CO_2} forms with no reactants remaining.

19
Choose one
1 point

A reaction has a theoretical yield of 4.8 g4.8\,\mathrm{g} and an actual yield of 3.6 g3.6\,\mathrm{g}. What is its percent yield?

  1. A

    25%25\%

  2. B

    75%75\%

  3. C

    133%133\%

  4. D

    480%480\%

20
Choose one
1 point

For H2SO4+2NaOH→Na2SO4+2H2O\mathrm{H_2SO_4 + 2NaOH \rightarrow Na_2SO_4 + 2H_2O}, what volume of 0.250 M0.250\,\mathrm{M} NaOH\mathrm{NaOH} is needed to react completely with 25.0 mL25.0\,\mathrm{mL} of 0.100 M0.100\,\mathrm{M} H2SO4\mathrm{H_2SO_4}?

  1. A

    5.00 mL5.00\,\mathrm{mL}

  2. B

    10.0 mL10.0\,\mathrm{mL}

  3. C

    20.0 mL20.0\,\mathrm{mL}

  4. D

    40.0 mL40.0\,\mathrm{mL}