Chemistry Flashcards
Balance the following equation
C2H5N + O2 → 8CO + H2O + 4NO2
4C2H5N + 13O2 → 8CO + 10H2O + 4NO2
Balance the following equation
Na (s) + O2 → Na2O
4Na (s) + O2 → 2Na2O
What is the oxidation number of free elements such as N2, P4, H2 and S8
They all have oxidation numbers of zero
Balance the following equation
C2H3Cl + O2 → CO2 + H2O + Cl2
4C2H3Cl + 12O2 → 8CO2 + 6H2O + 2Cl2
Balance the following equation
C4H10 (l) + O2 (g) → CO2 + H2O (l)
2C4H10 (l) + 13O2 (g) → 8CO2 + 10H2O (l)
a) Name elements in Group IA of the periodic table. b) What is their oxidation number?
a) Lithium (Li), Sodium (Na), Potassium (K), Rubidium (Rb), Cesium (Cs) and Francium (Fr)
b) +1
The oxidation number of a monatomic ion is equal to what?
The charge of the ion eg. Na+ the oxidation number is +1
a) An oxidising agent causes another atom in a redox reaction to be reduced or oxidised?
b) Is the oxidising agent then reduced or oxdised?
a) An oxdising agent caused an atom in a redox reaction to undergo oxidation.
b) The oxdising agent in a redox reaction is reduced.
What does the Mnemonic OIL RIG in terms of Redox reactions stand for?
OIL RIG
Oxidation is Loss, Reduction is Gain
Define a Bonsted-Lowry Acid
A species that donates hydrogen [H+] ions
Define a Bronsted-Lowry Base
A species that donates hydrogen [H+] ions
Why do Bronsted-Lowry acids and bases always occur in pairs?
Becasue the defination requires a transfer of a proton from the acid to the base. These are conjugate acid-base pairs.
When is a conjugate acid formed?
When a base gains a proton.
When is a conjugate base formed?
When an acid loses a proton.
Which is the base and which is its conjugate acid?
H3O+(aq) ⇔ H2O (aq) + H+ (aq)
H3O+ is the conjugate acid of the base H2O
What is the conjugate base in this equation?
HNO2 (aq) ⇔ NO2- (aq) + H+ (aq)
NO2- is the conjugate base of HNO2
What are the conjugate base and acids in the following reaction?
HCO3- (aq) + H2O (aq) ⇔ CO32- (aq) + H3O+
CO32- is the conjugate base of HCO3-
H3O+ is the conjugate acid of H2O
In aqueous solutions what happens to strong acids and bases?
In aqueous solutions what happens to weak acids and bases?
Strong acids and bases usually undergo complete ionisation (complete dissociation) in aqueous solutions.
Weak acids and bases only partially dissocate in the aqueous solutions.
Strong Acid + Strong Base ⇒ ?
Strong Acid + Strong Base ⇒ Salt + Water
eg.
HCl + NaOH ⇒ NaCl + H2O
If you have a strong acid, what will the conjugate base be weak or strong?
The stronger the acid the weaker its conjugate base and vice versa.
What is an amphoteric species?
An amphoteris species is a molecule that acts like an acid in the presence of a base, however acts like a base in the presence of an acid.
How does water act like an amphoteris species?
H2O can act either as an acid or a base depending on reacting species. Water acts like an acid by donating one of its hydrogen ions, and it acts as a base by accepting a hydrogen ion. As an amphoteric compound, water can react with itself in a process called auto-ionsation.
H2O (l) + H2O (l) ⇔ H3O+ (aq) + OH- (aq)
