Change in Ph, Precipitate Forms, Change in Color, Gas Given Off, Change in Heat Or Light

Name: ______KEY______Date: ______Chapter 8 Study Guide Describing Chemical Reactions Indication of Chemical Reactions List three indications of a chemical reaction: Change in pH, Precipitate forms, Change in Color, Gas Given off, Change in heat or light

Chemical Equations Given a formula equation, write the balanced chemical equation. Examples:

__3___ Fe3O4 + __8___ Al  ___4__ Al2O3 + ___9__ Fe

__2___ NaHCO3(s)  _____ Na2CO3(s) + _____ H2O(g) + _____ CO2(g)

___4__ H3BO3  _____ H2B4O7 + __5___ H2O

_____ B2O3 + ___3__ Mg  __3___ MgO + ___2__ B

_____ Zn3As2 + __6___HCl  ____2_ AsH3 + __3___ ZnCl2

__2___ Na2O2 + __2___ H2O  ___4__ NaOH + _____ O2

Given a word equation, write the balanced chemical equation. Examples: chlorine + sodium hydroxide  sodium chloride + sodium hypochlorite + water

Cl2 + 2 NaOH  NaCl + NaClO + H20

potassium fluoride + barium bromide  barium fluoride + potassium bromide

2KF + BaBr2  BaF2 + 2KBr

fluorine + sodium hydroxide  sodium fluoride + oxygen + water

2F2 + 4NaOH  4NaF + O2 + 2H2O

iron (III) hydroxide  iron (III) oxide + water

2Fe(OH)3  Fe2O3 + 3H2O Types of Reactions. a. Write the formula for each material correctly and then balance the equation. There are some reactions that require completion. b. For each reaction tell what type of reaction it is. You do not have to include phase indicators.

1. sulfur trioxide and water combine to make sulfuric acid (H2SO4).

SO3 + H2O  H2SO4

Type of Reaction___Synthesis______

2. lead (II) nitrate and sodium iodide react to make lead (II) iodide and sodium nitrate.

Pb(NO3)2 + 2NaI  PbI2 + 2NaNO3

Type of Reaction______Double Displacement______

3. calcium fluoride and sulfuric acid (H2SO4)make calcium sulfate and hydrogen fluoride (hydrofluoric acid, HF). CaF2 + H2SO4  CaSO4 + 2HF

Type of Reaction______Double Displacement______

4. calcium chloride will come apart when you heat it to leave

CaCl2  Ca + Cl2

Type of Reaction______Decomposition______

5. methane (CH4) gas burns in oxygen

CH4 + 2O2 CO2 + 2H2O

Type of Reaction______Combustion______

6. zinc and hydrochloric acid (HCl) react to form zinc chloride and hydrogen gas

Zn + 2HCl  ZnCl2 + H2

Type of Reaction______single displacement______Activity Series. Write a balanced molecular equation for each of the following aqueous reactions. Indicate whether or not the reaction will occur, and briefly explain why. Use the Activity Chart on page 266 in your text. This will be supplied on your test also. 1. silver+ copper (II) sulfateNR

silver is below copper and cannot replace it

2. gold (III) nitrate + zinc occurs because Zn is more active than Au

2Au(NO3)3 + 3Zn  2Au + 3Zn(NO3)2

3. chlorine+ lead (II) bromideoccurs because chlorine is more active than bromine

Cl2 + PbBr2  PbCl2 +Br2

acetic acid (HC2H3O2)+ silver No reaction-silver is below Hydrogen in reactivity

5. Copper + HCl  NR because copper is below hydrogen

6. Zinc + lead (II) nitrate  occurs because zinc is more active than lead

Zn + Pb(NO3)2  Zn(NO3)2 + Pb