Chapter 7 - Chemical Reactions

Question 1

Combustion Reactions

Answer 1

• a substance reacts w O, emitting heat and forming one or more O-containing compounds
• type of Oxidation-Reduction Rxn

Question 2

Precipitation Reactions

Answer 2

reactions in aqueous solutions that form a precipitate (a solid) when two aqueous solutions are mixed

Question 3

Signs of a Chem Rxn

Answer 3

• color change
• emission of light
• formation of solid
• emission/absorptionof heat
• formation of gas

Question 4

Reactants

Answer 4

substances on the left side of the chem equations

Question 5

Products

Answer 5

substances on the right side that are often the outcome

Question 6

Balanced Equation

Answer 6

in which the numbers of each type of atoms on both sides of the equation are equal

-to balance an equation, we insert coefficients in front of the chem formulas

Question 7

Aqueous Solution

Answer 7

• homogenous mixture of a substance with water

Question 8

Strong Electrolyte Solutions

Answer 8

-substances that completely dissociate into ionis in solutions are strong electrolytes

Question 9

Soluble

Answer 9

a compound is soluble in a particular liquid if it dissolves in the liquid

Question 10

Insoluble

Answer 10

a compound is insoluble if it DOES NOT dissolve in liquid

Question 11

Solubility Rules

Answer 11

Li, Na, K, NH4, NO3, C2H3O2 - solulable

Cl, Br, I - soluble except w Ag, Hg, or Pb

SO4 - soluble except w Ca, Sr, Ba, or Pb

Question 12

Insoluble Compounds

Answer 12

OH, S - except w Li, Na, K, NH4, Ca, Sr, Ba

CO3, PO4 except w Li, Na, K, NH4

Question 13

Soluble Ions w no exceptions (5)

Answer 13

Li, Na, K, NH4, NO3, C2H3O2

Question 14

Precipitate

Answer 14

a solid that is formed from a reaction

-only insoluble compounds form precipitate

Question 15

Molecular Equations

Answer 15

completely neutral formulas for every compound in the reaction

Question 16

Complete Ionic Equations

Answer 16

• shows each reactant and product as their are actually present in solution
  ex) Ag+ + NO3- + Na+ + Cl- => AgCl + Na+ + NO3-

Question 17

Spectator Ions

Answer 17

in complete ionic equations, some of the ions in solution appear unchanged on both sides of the equation

• these spectator ions do not participate in the rxn
• spectator ions can be omitted to simplify the equations - instead of complete, they are net ionic equations

ex) Ag+ + NO3- + Na+ + Cl- => AgCl + Na+ + NO3-
the SPECTATORS are Na and NO3

Question 18

Net Ionic Equations

Answer 18

equations which only show the species that actually participate in the rxn (unlike complete ionic equations)

ex) COMPLETE IONIC EQUATION: Ag+ + NO3- + Na+ + Cl- => AgCl + Na+ + NO3-
the SPECTATORS Na and NO3 are removed:
NET IONIC EQUATION: Ag+ + Cl- => AgCl

Question 19

Acid-Base Reaction

aka Neutralization Rxn

Answer 19

• reactions that form water upon mixing of an acid and a base
• the acid’s H combines with the base’s OH to form H2O

ex) HCl +NaOh -> H2O + NaCl

Question 20

Gas Evolution Reactions

Answer 20

aqueous reactions that form a gas as a product

-The intermediate product H2CO3 is unstable and becomes H2O(aq) + CO2(g)

Question 21

compounds that undergo Gas Evolution

Answer 21

H2CO3 - CO2(g)
H2SO3 - SO2(g)
NH4OH - NH3(g)
H2S (g)

Question 22

Oxidation-Reduction Reaction

aka Redox Rxn

Answer 22

• involved the transfer of electrons
• responsible for the rusting of iron, bleaching of hair, and production of electricity in batteries
• oxidation (loss of e) and reduction (gain of e) must occur together
• substance reacts w elemental O
• metal reacts w nonmetal
• one substance transfers e to another substance

ex) rusting of iron:
4Fe(s) + 3O2(g) => 2Fe2O3(s)

Question 23

Oxidation

Answer 23

the loss of electrons

Question 24

Reduction

Answer 24

the gain of electrons

Question 25

Combustion Reaction

Answer 25

a type of EXOTHERMIC (emit heat) Redox Rxn | -the reaction of a substance w O2 to form 1 or more O-containing compounds; often including H2O

Question 26

4 types of Chem Rxn

Answer 26

1 Precipitation Rxn 2 Acid-Base Rxn 3 Gas Evolution Rxn (many are also an acid/base rxn) 4 Oxidation Rxn (including Combustion Rxn0

Question 27

4 Types of Reactions

Answer 27

Synthesis/Combination Decomposition Single-Displacement Double-Displacement

Question 28

A + B ==> AB

Answer 28

synthesis rxn/combo rxn

Question 29

AB ==> A + B

Answer 29

decomposition rxn

Question 30

A + BC ==> AC + B

Answer 30

single displacement rxn

Question 31

AB + CD ==> AD + CB

Answer 31

double displacement

Question 32

Synthesis/Combination Rxn

Answer 32

simple substances combine to form more complex substances ex) 2Na + Cl2 => 2NaCl or CaO + CO2 => CaCO3

Question 33

Decomposition Rxn

Answer 33

a complex substance decomposes into simpler substances ex) 2H2O => 2H + O2

Question 34

Displacement Rxns

Answer 34

one element displaces another in a compound ex) Zn + CuCl2 => ZnCl2 + Cu

Question 35

Double Displacement Rxn

Answer 35

2 elements or groups of elements in 2 different compounds exchange placed to form 2 NEW compounds ex) HCl +NaOH => H2O + NaCl