1,001 Chemistry Practice Problems For Dummies (2014)

Part I. The Questions

Chapter 9. Chemical Reactions

Every chemical reaction begins with the formula of one or more substances (reactants) followed by an arrow and ends with the formula of one or more substances (products). There are many types of chemical reactions; however, only a few basic types appear in this chapter. Redox reactions tend to be more difficult to balance than the other reactions here, so you use a systematic approach to balance most redox reactions.

The Problems You’ll Work On

In this chapter, you work with chemical reactions in the following ways:

check Identifying types of reactions

check Balancing chemical equations

check Balancing redox reactions

Note: See the Appendix if you need to check the periodic table.

What to Watch Out For

Remember the following when working on chemical reactions:

check When balancing equations, never change a chemical formula; change only the coefficients.

check There are only a few basic reaction types here, so don’t invent new ones. But note that a reaction may fit into more than one category.

check Ionic equations contain ions.

check Acid-base reactions always produce a salt and usually produce water.

check Redox reactions must have an oxidation and a reduction.

Classifying Reactions from Chemical Equations

546–555 Given the chemical equation, name the type of reaction (combination, combustion, decomposition, single displacement, or double displacement).

546. What type of reaction is the following reaction?

9781118549322-eq09001.eps

547. What type of reaction is the following reaction?

9781118549322-eq09002.eps

548. What type of reaction is the following reaction?

9781118549322-eq09003.eps

549. What type of reaction is the following reaction?

9781118549322-eq09004.eps

550. What type of reaction is the following reaction?

9781118549322-eq09005.eps

551. What type of reaction is the following reaction?

9781118549322-eq09006.eps

552. What type of reaction is the following reaction?

9781118549322-eq09007.eps

553. What type of reaction is the following reaction?

9781118549322-eq09008.eps

554. What type of reaction is the following reaction?

9781118549322-eq09009.eps

555. What type of reaction is the following reaction?

9781118549322-eq09010.eps

Classifying Reactions from Word Equations

556–565 Given the word equation, name the type of chemical reaction (combination, combustion, decomposition, single displacement, or double displacement).

556. What type of reaction is the following reaction?

9781118549322-eq09011.eps

557. What type of reaction is the following reaction?

9781118549322-eq09012.eps

558. What type of reaction is the following reaction?

9781118549322-eq09013.eps

559. What type of reaction is the following reaction?

9781118549322-eq09014.eps

560. What type of reaction is the following reaction?

9781118549322-eq09015.eps

561. What type of reaction is the following reaction?

9781118549322-eq09016.eps

562. What type of reaction is the following reaction?

9781118549322-eq09017.eps

563. What type of reaction is the following reaction?

9781118549322-eq09018.eps

564. What type of reaction is the following reaction?

9781118549322-eq09019.eps

565. What type of reaction is the following reaction?

9781118549322-eq09020.eps

Predicting Reactions

566–575 Given the reactants, predict the type of chemical reaction.

566. Predict the type of reaction these reactants would undergo:

9781118549322-eq09021.eps

567. Predict the type of reaction this reactant would undergo when heated:

9781118549322-eq09022.eps

568. Predict the type of reaction these reactants would undergo:

9781118549322-eq09023.eps

569. Predict the type of reaction these reactants would undergo:

9781118549322-eq09024.eps

570. Predict the type of reaction these reactants would undergo:

9781118549322-eq09025.eps

571. Predict the type of reaction these reactants would undergo:

9781118549322-eq09026.eps

572. Predict the type of reaction these reactants would undergo:

9781118549322-eq09027.eps

573. Predict the type of reaction these reactants would undergo:

9781118549322-eq09028.eps

574. Predict the type of reaction this reactant would undergo when heated:

9781118549322-eq09029.eps

575. Predict the type of reaction these reactants would undergo:

9781118549322-eq09030.eps

Balancing Chemical Reactions

576–585 Balance the chemical reaction.

576. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09031.eps

577. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09032.eps

578. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09033.eps

579. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09034.eps

580. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09035.eps

581. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09036.eps

582. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09037.eps

583. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09038.eps

584. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09039.eps

585. What are the coefficients of the following equation when it’s balanced?

9781118549322-eq09040.eps

Balancing Reactions from Word Equations

586–595 Given the word equation, balance the chemical reaction.

586. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09041.eps

587. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09042.eps

588. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09043.eps

589. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09044.eps

590. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09045.eps

591. What is the sum of the coefficients of the following reaction when it’s balanced?

9781118549322-eq09046.eps

592. What is the sum of the coefficients of the following reaction when it’s balanced?

9781118549322-eq09047.eps

593. What is the sum of the coefficients of the following reaction when it’s balanced?

9781118549322-eq09048.eps

594. What is the sum of the coefficients of the following reaction when it’s balanced?

9781118549322-eq09049.eps

595. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09050.eps

Predicting Products and ­Balancing Reactions

596–605 Given the reactants, predict the products and balance the chemical reaction.

596. When the following reaction is completed and balanced, what is the coefficient on the barium hydroxide?

9781118549322-eq09051.eps

597. When the following reaction is completed and balanced, what is the coefficient on the nickel(II) chloride?

9781118549322-eq09052.eps

598. The compound in the following reaction is heated. What is the sum of the coefficients when the reaction is completed and balanced? (Hint: One of the products of heating this compound is another form of lead oxide.)

9781118549322-eq09053.eps

599. When the following reaction is completed and balanced, what is the coefficient on the silver nitrate?

9781118549322-eq09054.eps

600. When the following reaction is completed and balanced, what is the sum of the coefficients? (Hint: The products are two elements.)

9781118549322-eq09055.eps

601. Complete and balance the following reaction:

9781118549322-eq09056.eps

602. When the following reaction is completed and balanced, what is the sum of the coefficients? (Hint: One of the products is water.)

9781118549322-eq09057.eps

603. When the following reaction is completed and balanced, what is the coefficient on the nitrogen dioxide? (Hint: The products are two elements.)

9781118549322-eq09058.eps

604. Complete and balance the following reaction:

9781118549322-eq09059.eps

605. When the following reaction is completed and balanced, what is the coefficient on the copper(II) sulfate?

9781118549322-eq09060.eps

Redox and Acid-Base ­Reactions

606–621 Answer the following questions on redox and acid-base (neutralization) reactions.

606. What is the oxidation number of Mn in KMnO4?

607. What is the oxidation number of Br in NaBrO3?

608. What is the oxidation number of Cr in Cr2O72–?

609. What is the oxidation number of S in S2O32–?

610. When a substance loses electrons during the course of a reaction, it goes through which process?

611. When a substance gains electrons during the course of a reaction, it goes through which process?

612. Which substance in the following forward reaction is oxidized?

9781118549322-eq09061.eps

613. Which substance in the following forward reaction is reduced?

9781118549322-eq09062.eps

614. Which substance in the following forward reaction is the reducing agent?

9781118549322-eq09063.eps

615. Which substance in the following forward reaction is the oxidizing agent?

9781118549322-eq09064.eps

616. How many electrons are necessary to balance the following half-reaction that takes place in an acidic environment?

9781118549322-eq09065.eps

617. How many electrons are necessary to balance the following half-reaction that takes place in a basic environment?

9781118549322-eq09066.eps

618. How many hydrogen ions do you need to balance the following oxidation-reduction reaction?

9781118549322-eq09067.eps

619. What is the coefficient of the OH when the following oxidation-reduction reaction is balanced?

9781118549322-eq09068.eps

620. What are the coefficients of the following reaction when it’s balanced?

9781118549322-eq09069.eps

621. What is the coefficient of 9781118549322-eq09070.eps when the ­following reaction is balanced?

9781118549322-eq09071.eps