General Chemistry Board |Exam Questions
with 100% verified Answers
law of constant composition - ✔️✔️-for a pure sample a given compound will contain the same
elements in an identical mass ratio
Empirical formula vs. molecular formula - ✔️✔️-empirical formula: simplest whole-number ration
of the elements of the compound (CH)
-molecular formula: exact number of atoms of each element in a compound and is a multiple of
the empirical formula (C6H6)
Types of Chemical Reactions - ✔️✔️-combination reactions (A+B->C)
-decomposition reactions (A->B+C)
-single-displacement (A+BC->AB+C) (usually ox-redox)
-double-displacement or metathesis reactions
(AB+CD->AC+DB(s)) usually one product changes state
-combustion (CH4+2O2->CO2+2H2O)
-neutralization reaction is a double replacement with salt and water as probable product
HCl+NaOH->NaCl+H2O
monatomic anions - ✔️✔️H- hydride
S2- sulfide
P3- Phosphide
IDE
Oxyanions S,N - ✔️✔️NO2- Nitrite HNO2= nitrous acid
NO3- Nitrate HNO3= nitric acid
SO3 2- Sulfite
,SO4 2- Sulfate H2SO4= sulfuric acid
litest anions have fewer oxygens, heaviest anions ATE the most oxygens
extended oxyanions ClO-ClO4 - ✔️✔️ClO- hypochlorate
ClO2- chlorite
ClO3- chlorate
ClO4- perchlorate
ammonium
acetate
cyanide
permanganate
chromate
dichromate - ✔️✔️ammonium NH4+
acetate C2H3O2 -
cyanide CN-
permanganate MnO4-
chromate CrO4 2-
dichromate Cr2O7 2-
Bronsted-Lowry acids and bases - ✔️✔️acids- donate hydrogens/protons
nucleophiles vs. bases - ✔️✔️-have either lone pairs or pi bonds that can form new bonds
make great bases, but being a good nucleophile is based on relative reaction rates (kinetic
property), while a good base is based on equilibrium position of a reaction (thermodynamic
property)
-leaving group must be less reactive then the nucleophile
, four factors affecting nucleophilicity - ✔️✔️-Charge: nucleophilicity increases with increasing
electron density
-EN: decreases with increased EN because it is less likely to share electrons
-steric hindrance: bulkier molecules are less nucelophilic
-solvent: protic solvents inhibit nucleophilicity
common protic/aprotic solvents - ✔️✔️protic-can hydrogen bond
carboxylic acids, water/alcohols, ammonia/amines
nucleophilicity decreases down the periodic table
aprotic: cant hydrogen bond
-DMF, DMSO, acetone
nucleophilicity increases up the periodic table
EX. protic I>Br>Cl>f (HI is a strong acid)
aprotic F>Cl>Br>I
electrophilicity of cooh derivatives - ✔️✔️-anhydrides are the most reactive, then cooh and
esters, then amides
SN1 reactions - ✔️✔️-first step is rate-limiting, the formation of a carbocation, then the
nucleophile attacks
-more substituted carbocations are more stable because the alkyl groups can act as electron
donors
-planar intermediate
SN2 reactions - ✔️✔️backside attack of the leaving group
-inversion of relative configuration (R->S)
-its one step, so its a concerted reaction
-less sterically hindered is better
with 100% verified Answers
law of constant composition - ✔️✔️-for a pure sample a given compound will contain the same
elements in an identical mass ratio
Empirical formula vs. molecular formula - ✔️✔️-empirical formula: simplest whole-number ration
of the elements of the compound (CH)
-molecular formula: exact number of atoms of each element in a compound and is a multiple of
the empirical formula (C6H6)
Types of Chemical Reactions - ✔️✔️-combination reactions (A+B->C)
-decomposition reactions (A->B+C)
-single-displacement (A+BC->AB+C) (usually ox-redox)
-double-displacement or metathesis reactions
(AB+CD->AC+DB(s)) usually one product changes state
-combustion (CH4+2O2->CO2+2H2O)
-neutralization reaction is a double replacement with salt and water as probable product
HCl+NaOH->NaCl+H2O
monatomic anions - ✔️✔️H- hydride
S2- sulfide
P3- Phosphide
IDE
Oxyanions S,N - ✔️✔️NO2- Nitrite HNO2= nitrous acid
NO3- Nitrate HNO3= nitric acid
SO3 2- Sulfite
,SO4 2- Sulfate H2SO4= sulfuric acid
litest anions have fewer oxygens, heaviest anions ATE the most oxygens
extended oxyanions ClO-ClO4 - ✔️✔️ClO- hypochlorate
ClO2- chlorite
ClO3- chlorate
ClO4- perchlorate
ammonium
acetate
cyanide
permanganate
chromate
dichromate - ✔️✔️ammonium NH4+
acetate C2H3O2 -
cyanide CN-
permanganate MnO4-
chromate CrO4 2-
dichromate Cr2O7 2-
Bronsted-Lowry acids and bases - ✔️✔️acids- donate hydrogens/protons
nucleophiles vs. bases - ✔️✔️-have either lone pairs or pi bonds that can form new bonds
make great bases, but being a good nucleophile is based on relative reaction rates (kinetic
property), while a good base is based on equilibrium position of a reaction (thermodynamic
property)
-leaving group must be less reactive then the nucleophile
, four factors affecting nucleophilicity - ✔️✔️-Charge: nucleophilicity increases with increasing
electron density
-EN: decreases with increased EN because it is less likely to share electrons
-steric hindrance: bulkier molecules are less nucelophilic
-solvent: protic solvents inhibit nucleophilicity
common protic/aprotic solvents - ✔️✔️protic-can hydrogen bond
carboxylic acids, water/alcohols, ammonia/amines
nucleophilicity decreases down the periodic table
aprotic: cant hydrogen bond
-DMF, DMSO, acetone
nucleophilicity increases up the periodic table
EX. protic I>Br>Cl>f (HI is a strong acid)
aprotic F>Cl>Br>I
electrophilicity of cooh derivatives - ✔️✔️-anhydrides are the most reactive, then cooh and
esters, then amides
SN1 reactions - ✔️✔️-first step is rate-limiting, the formation of a carbocation, then the
nucleophile attacks
-more substituted carbocations are more stable because the alkyl groups can act as electron
donors
-planar intermediate
SN2 reactions - ✔️✔️backside attack of the leaving group
-inversion of relative configuration (R->S)
-its one step, so its a concerted reaction
-less sterically hindered is better
