Chemical reactions flashcards

Chemical reactions involve the breaking of bonds in reactants and the formation of new bonds in products, resulting in substances with different chemical identities. Students must be able to classify reactions as synthesis, decomposition, single replacement, double replacement, or combustion, and write balanced chemical equations that obey conservation of mass and charge. Understanding net ionic equations requires identifying spectator ions and writing only the species that actually change. Oxidation-reduction reactions involve electron transfer, tracked through oxidation numbers. Students should recognize evidence of a chemical reaction such as gas production, precipitate formation, color change, or energy release. Predicting products, including solubility rules for precipitation reactions and activity series for replacement reactions, is essential for success on the AP exam.

1. Card 1

   What is a chemical reaction?

   A process in which reactants are converted into products through the breaking and forming of chemical bonds, producing substances with new identities.

2. Card 2

   What does it mean to balance a chemical equation?

   Adjusting coefficients so the number of each type of atom is equal on both sides, satisfying the law of conservation of mass.

3. Card 3

   What is a synthesis reaction?

   A reaction where two or more substances combine to form a single product; general form: A + B → AB.

4. Card 4

   What is a decomposition reaction?

   A single compound breaks down into two or more simpler substances; general form: AB → A + B. Often requires energy input.

5. Card 5

   What distinguishes a single replacement from a double replacement reaction?

   In single replacement, one element displaces another in a compound. In double replacement, two compounds exchange ions with each other.

6. Card 6

   What are spectator ions?

   Ions that appear on both sides of an ionic equation unchanged; they do not participate in the reaction and are omitted from the net ionic equation.

7. Card 7

   How do you write a net ionic equation?

   Write the full ionic equation, cancel spectator ions on both sides, and show only the species that undergo a chemical change.

8. Card 8

   What is an oxidation-reduction (redox) reaction?

   A reaction involving electron transfer; the species losing electrons is oxidized and the one gaining electrons is reduced.

9. Card 9

   How are oxidation numbers used in redox reactions?

   Oxidation numbers track electron ownership; an increase indicates oxidation and a decrease indicates reduction across the reaction.

10. Card 10

    What are the solubility rules used for in chemical reactions?

    They predict whether an ionic compound formed in a double replacement reaction will be a precipitate (insoluble) or remain dissolved in solution.

11. Card 11

    What is the activity series and how is it applied?

    A ranking of metals by reactivity; a more active metal will displace a less active metal from its compound in a single replacement reaction.

12. Card 12

    What are four observable signs that a chemical reaction has occurred?

    Formation of a precipitate, gas production, color change, or a significant energy change such as heat or light being released or absorbed.

• Many students change subscripts in a chemical formula to balance an equation instead of only adjusting coefficients, which creates entirely different compounds.
• Students often forget to separate strong electrolytes into their individual ions when writing ionic equations, leading to incorrect identification of spectator ions.
• A common error is assuming that any reaction involving oxygen is a redox reaction, when in fact only reactions with actual changes in oxidation numbers involve electron transfer.

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