Chapter 3 notes

Flashcard maker : Robert Lollar

balance the following equations:

(a) C2H6 + O2 –> CO2 + H2O

(b) PCl5 + H2O –> H3PO4 + HCl

(c) Fe2(SO4)3 + NH3 + H2O –> Fe(OH)3 + (NH4)2SO4

(a) 2C2H6 + 7O2 –> 4CO2 + 6H2O

(b) PCl5 + 4H2O –> H3PO4 + 5HCl

(c) Fe2(SO4)3 + 6NH3 + 6H2O –> 2Fe(OH)3 + 3(NH4)2SO4

balance the following equations:

(a) KNO3 –> KNO2 + O2

(b) NH4NO3 –> N2O + H2O

(c) HCl + CaCO3 –> CaCl2 + H2O + CO2

(a) 2KNO3 –> 2KNO2 + O2

(b) NH4NO3 –> N2O + 2H2O

(c) 2HCl + CaCO3 –> CaCl2 + H2O + CO2

what is an electrolyte?
a substance that, when dissolved in water, results in a solution that can conduct electricity
what is a nonelectrolyte?
a substance that, when dissolved in water, results in a solution that does not conduct electricity
what is a strong electrolyte?

100% dissociated into ions. This is an electrolyte that exists in solution almost entirely as ions

 

NaCl(s) –H2O–> Na+(aq) Cl(aq) 

All soluble ionic compounds are strong electrolytes

what is a weak electrolyte?

is partially dissolved into ions. This is an electrolyte that disolves in water to give a relatively small percentage of ions. There is an equalibrium between the dissociated and non-dissociated species

 

CH3CO2H(aq) ↔ CH3CO2(aq) + H+(aq)

what is a non-electrolyte?

does not conduct electricity as there are no ions present. Solutions of molecular compounds such as sugars and alcohols do not ionize or dissociate in aqueous solution

 

C6H2O6(s) –H2O–> C6H12O6(aq)

Ex: sugars and alcohols

what is a precipitation reaction?
when 2 solutions of ionic compounds are mixed and a water-insoluble solid product known as a precipitate is formed
what is an exchange reaction?

a reaction in which the ions of the reactants exchange “partners”

 

AB + CD = AD + CB

AgNO3(aq) + NaCl(aq) –> AgCl(s) + NaNO3(aq)

what is solubility?
the maximum amount of solute that will dissolve in a given quantity of solvent at a specific temperature

predict whether each of the following ionic compounds is likely to be soluble in water:

 

(a) LiNO3

(b) CaCl2

(c) CuO

(d) NaCH3CO2

(a) LiNO3                 soluble

(b) CaCl2                 soluble

(c) CuO                insoluble

(d) NaCH3CO2         soluble

when 2 ionic compounds in aqueous solution react to form a solid precipitate, they do so by exchanging ions. Predict the products in the following reactions:

 

(a) AgNO3(aq) + KCl(aq) –>

(b) Pb(NO3)2(aq) + K2CrO4(aq) –>

(c) Pb(NO3)2(aq) + (NH4)2S(aq) –>

(d) FeCl3(aq) + 3NaOH(aq) –>

(a) AgNO3(aq) + KCl(aq) –>

AgCl(s) + KNO3(aq)

(b) Pb(NO3)2(aq) + K2CrO4(aq) –>

PbCrO4(s) + 2KNO3(aq)

(c) Pb(NO3)2(aq) + (NH4)2S(aq) –>

PbS(s) + 2NH4NO3(aq)

(d) FeCl3(aq) + 3NaOH(aq) –>

Fe(OH)3(s) + 3NaCl(aq)

what is a molecular equation?

a chemical equation in which the reactants and products are written as molecules or whole units

 

Ba(NO3)2(aq) + NaSO4(aq) –> 2NaNO3(aq) + BaSO4(aq)

what is a complete ionic equation?

a chemical equation in which the dissolved species are written as separate ions in aqueous solution

 

Ba2+(aq) + 2NO3(aq) + 2Na+(aq) + SO42-(aq) –>

2Na+(aq) + 2NO3(aq) + BaSO4(s)

(Na+ and NO3 are spectator ions)

what is a net ionic equation?

an ionic equation from which the spectator ions have been cancelled

 

Ba2+(aq) + SO42-(aq) –> BaSO4(s)

write the net ionic equation for the reaction of silver nitrate with sodium chloride

Ag+(aq) + Cl(aq) –>AgCl(s)

write the net ionic equation for the reaction of lead (II) nitrate and potassium iodide
PB2+(aq) + 2I(aq) –> PbI2(s)
write the net ionic equation for the reaction of iron (III) chloride and ammonium hydroxide
Fe3+(aq) + 3OH(aq) –> Fe(OH)3(s)
write the net ionic equation for the reaction of iron (II) nitrate and sodium chloride

Fe(NO3)2(aq) + 2NaCl(aq) –> 2NaNO3(aq) + FeCl2(aq)

 

–> no precipitate forms

write the net ionic equation for the reaction of aluminum sulfate and sodium hydroxide
Al3+(aq) + 3OH(aq) –> Al(OH)3(s)
write the net ionic equation for the reaction of sodium carbonate and calcium chloride
Ca2+(aq) + CO32-(aq) –> CaCO3(s)
what is an arrhenius acid?

a sunstance that produces H+ ions or H3O+ ions in water

 

HCl + H2O –> H3O+ + Cl

HCl –H2O–> H+ + Cl

what is an arrhenius base?

a substance that produces OH ions in water

 

NH3 + H2O ↔ NH4+ + OH

what is a bronsted acid?

a proton donor

 

HNO3 + H2O –> H3O+ + NO3

must contain at least one ionizable proton!

what is a bronsted base?

a proton acceptor

 

NH3 + H2O ↔ NH4+ + OH

what is a strong acid?

an acid that ionizes completely in water; it is a strong electrolyte

 

Ex: HCl(aq) –> H+(aq) + Cl(aq)

strong acids: HCl, HBr, HI, HNO3, HClO4, H2SO4

what is a weak acid?

an acid that only partly ionizes in water; it is a weak electrolyte

 

Ex: CH3CO2H(aq) ↔ H+(aq) + CH3CO2(aq)

some weak acids: HF, HNO2, CH3CO2H, HCN, H3PO4

what is a strong base?

a base that ionizes completely in water; it is a strong electrolyte

 

NaOH(s) –> Na+(aq) + OH(aq)

Strong bases: LiOH, NaOH, KOH, Ba(OH)2, group I and II hydroxide

what is a weak base?

a base that only partly ionizes in water; it is a weak electrolyte

 

NH3(aq) + H2O(l) ↔ NH4+(aq) + OH(aq)

 

Ex: ammonia

what is a neutralization reaction?

a reaction between an acid and a base that results in an ionic compound (salt) and possibly water

 

Acid + Base –> Salt + Water

what is a salt?
an ionic compound whose cation comes from a base and anion comes from an acid
what is the reaction for a strong acid and base?

HCl(aq) + NaOH(aq) –> NaCl(aq) + H2O(l)

H+(aq) + Cl(aq) + Na+(aq) + OH(aq) –> Na+(aq) +Cl(aq) + H2O(l)

H+(aq) + OH(aq) –>H2O(l)

reaction of a weak acid and a strong base

HCN(aq) + KOH(aq) –> KCN(aq) + H2O(l)

HCN(aq) + K+(aq) + OH(aq) –> K+(aq) + CN(aq) + H2O(l)

HCN(aq) + OH(aq) –> CN(aq) + H2O(l)

what is an acidic oxide?

oxides of non-metals are called acidic oxides (form acids with water)

 

CO2(g) + H2O(l) –> H2CO3(aq)

what is a basic oxide?

oxides of metals (form bases with water)

 

BaO(s) + H2O(l) –> Ba(OH)2(aq)

cetain salts do what

(corbonates, CO32-, sulfites, SO32-, sulfides, S2-)

react with acids to form a gaseous product

gases

CO2(g)

H2S(g)

SO2(g)

NH3(g)

ammonium salts to what?
react with strong bases to form a gaseous product
write a balanced equation for the reaction that occurs when nickle (II) carbonate is treated with sulfuric acid

NiCO3(s) + H2SO4(aq) –> NiSO4(aq) + H2CO3(aq)

–> NiSO4(aq) + H2O(l) + CO2(aq)

write a balanced equation for the reaction of ammonium sulfate with sodium hydroxide

NH4+ SO42-

(NH4)2SO4(aq) + 2NaOH(aq) –> 2NH3(g) + Na2SO4(aq) + 2H2O(l)

what is a redox-reaction?
a reaction in which electrons are transferred between species or in which atoms change oxidation number
if you dip an iron nail into a blue solution of copper (II) sulfate, the iron becomes coated with copper. What is the equation?

Fe(s) + CuSO4(aq) –> FeSO4(aq) + Cu(s)

Fe(s) + Cu2+(aq) + SO42-(aq) –> Fe2+(aq) + SO42-(aq) + Cu(s)

Fe(s) + Cu2+(aq) –> Fe2+(aq) + Cu(s)

what is a half-reaction?

Fe(s) –> Fe2+(aq) + 2e

Fe is oxidized

Cu2+(aq) + 2e –> Cu(s)

Cu2+ is reduced

what is oxidation?

loss of electron (gain in oxidation #)

 

Oxidation

Is         

Loss      

what is a reduction?

gain of electron (decrease in ocidation #)

 

Reduction

Is          

Gain       

what is an oxidizing agent?
a species that oxidises another species; reduction
what is a reducing agent?
a species that reduces another species; oxidized

zinc metal reacts with copper (II) sulfate to form copper metal. What is the reducing agent in the reaction?

 

Zn(s) + CuSO4(aq) –> ZnSO4(aq) + Cu(s)

Zn(s) + Cu2+(aq) –> Zn2+(aq) + Cu(s)

Zn is the reducing agent

copper wire reacts with silver nitrate to form silver metal. what is the oxidizing agent in the reaction?

 

Cu(s) + 2AgNO3(aq) –> Cu(NO3)2(aq) 2Ag(s)

Cu(s) + Ag+(aq) –> Cu2+(aq) + Ag(s)

Ag+ is the oxidizing agent

(oxidation)

free elements (uncombined state) have an oxidation number of zero. they are what?

Na, Be, K, Pb, H2, O2, P4 = 0

(oxidation)

in monatomic ions, the oxidation number is equal to the charge on the ion. what are they?

Li+, Li = +1

Fe3+, Fe = +3

O2-, O = -2

(oxidation)

the oxidation number of oxygen is usually -2. In H2Oand O22- it is what?

-1
the oxidation number of hydrogen is +1 except when it is bonded to metals in bianary compounds. In these cases, its oxidation number is what?
-1

(a) Group IA metals are what charge?

(b) Group IIA metals are what charge?

(c) Fluorine is always what charge?

(a) +1

(b) +2

(c) -1

the sum of the oxidation numbers of all the atoms in a molecule or ion is always equal to the charge on the what?
molecule or ion
oxidation numbers do not have to be what?
integers
write the oxidation numbers of all the elements in HCO3

H = +1

C = +4

O = -2

 

(+1 X 1) + x + (-2 X 3) = -1

                    1 + x – 6 = -1

                          x – 5 = -1

                               x = +4

write the oxidation numbers of all the elements in NaIO3

Na = +1

I = +5

O = -2

 

(+1 X 1) + x + (-2 X 3) = 0

                                 x = +5

write the oxidation numbers of all the elements in IF7

I = +7

F = -1

 

x + (-1 X 7) = 0

                  x = +7

write the oxidation numbers of all the elements in K2Cr2O7

K = +1

Cr = +6

O = -2

 

(+1 X 2) + 2x + (-2 X 7) = 0

                               2x = +12

                                 x = 6

Get instant access to
all materials

Become a Member