Chapter 3 notes – Flashcards

Unlock all answers in this set

Unlock answers
question

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

answer

(a) 2C2H6 + 7O2 --> 4CO2 + 6H2O

(b) PCl5 + 4H2O --> H3PO4 + 5HCl

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

question

balance the following equations:

(a) KNO3 --> KNO2 + O2

(b) NH4NO3 --> N2O + H2O

(c) HCl + CaCO3 --> CaCl2 + H2O + CO2

answer

(a) 2KNO3 --> 2KNO2 + O2

(b) NH4NO3 --> N2O + 2H2O

(c) 2HCl + CaCO3 --> CaCl2 + H2O + CO2

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

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

question
what is a weak electrolyte?
answer

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)

question
what is a non-electrolyte?
answer

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

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

a reaction in which the ions of the reactants exchange "partners"

 

AB + CD = AD + CB

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

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

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

 

(a) LiNO3

(b) CaCl2

(c) CuO

(d) NaCH3CO2

answer

(a) LiNO3                 soluble

(b) CaCl2                 soluble

(c) CuO                insoluble

(d) NaCH3CO2         soluble

question

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) -->

answer

(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)

question
what is a molecular equation?
answer

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)

question
what is a complete ionic equation?
answer

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)

question
what is a net ionic equation?
answer

an ionic equation from which the spectator ions have been cancelled

 

Ba2+(aq) + SO42-(aq) --> BaSO4(s)

question

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

answer

Ag+(aq) + Cl-(aq) -->AgCl(s)

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

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

 

--> no precipitate forms

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

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

 

HCl + H2O --> H3O+ + Cl-

HCl --H2O--> H+ + Cl-

question
what is an arrhenius base?
answer

a substance that produces OH- ions in water

 

NH3 + H2O ↔ NH4+ + OH-

question
what is a bronsted acid?
answer

a proton donor

 

HNO3 + H2O --> H3O+ + NO3-

must contain at least one ionizable proton!

question
what is a bronsted base?
answer

a proton acceptor

 

NH3 + H2O ↔ NH4+ + OH-

question
what is a strong acid?
answer

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

question
what is a weak acid?
answer

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

question

what is a strong base?

answer

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

question
what is a weak base?
answer

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

 

NH3(aq) + H2O(l) ↔ NH4+(aq) + OH-(aq)

 

Ex: ammonia

question
what is a neutralization reaction?
answer

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

 

Acid + Base --> Salt + Water

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

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)

question
reaction of a weak acid and a strong base
answer

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)

question
what is an acidic oxide?
answer

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

 

CO2(g) + H2O(l) --> H2CO3(aq)

question
what is a basic oxide?
answer

oxides of metals (form bases with water)

 

BaO(s) + H2O(l) --> Ba(OH)2(aq)

question
cetain salts do what
answer

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

react with acids to form a gaseous product

question
gases
answer

CO2(g)

H2S(g)

SO2(g)

NH3(g)

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

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

--> NiSO4(aq) + H2O(l) + CO2(aq)

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

NH4+ SO42-

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

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

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)

question
what is a half-reaction?
answer

Fe(s) --> Fe2+(aq) + 2e-

Fe is oxidized

Cu2+(aq) + 2e- --> Cu(s)

Cu2+ is reduced

question
what is oxidation?
answer

loss of electron (gain in oxidation #)

 

Oxidation

Is         

Loss      

question
what is a reduction?
answer

gain of electron (decrease in ocidation #)

 

Reduction

Is          

Gain       

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

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)

answer

Zn(s) + Cu2+(aq) --> Zn2+(aq) + Cu(s)

Zn is the reducing agent

question

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)

answer

Cu(s) + Ag+(aq) --> Cu2+(aq) + Ag(s)

Ag+ is the oxidizing agent

question

(oxidation)

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

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

(oxidation)

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

answer

Li+, Li = +1

Fe3+, Fe = +3

O2-, O = -2

question

(oxidation)

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

answer
-1
question
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?
answer
-1
question

(a) Group IA metals are what charge?

(b) Group IIA metals are what charge?

(c) Fluorine is always what charge?

answer

(a) +1

(b) +2

(c) -1

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

H = +1

C = +4

O = -2

 

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

                    1 + x - 6 = -1

                          x - 5 = -1

                               x = +4

question
write the oxidation numbers of all the elements in NaIO3
answer

Na = +1

I = +5

O = -2

 

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

                                 x = +5

question
write the oxidation numbers of all the elements in IF7
answer

I = +7

F = -1

 

x + (-1 X 7) = 0

                  x = +7

question
write the oxidation numbers of all the elements in K2Cr2O7
answer

K = +1

Cr = +6

O = -2

 

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

                               2x = +12

                                 x = 6

Get an explanation on any task
Get unstuck with the help of our AI assistant in seconds
New