Chemistry MUST MEMORISE

Equation for reaction of sodium oxide and water

Na2O(s) + H2O(l) → 2NaOH(aq)

pH of solution for reaction of sodium oxide and water

pH 13

Equation for reaction of magnesium oxide and water

MgO(s) + H2O(l) ←/→ Mg(OH)2(aq)

Dissolution is reversible where small amount of MgO reacts with water

Because MgO highly exothermic lattice energy

pH of solution for reaction of magnesium oxide and water

pH 9

Equation for reaction of aluminium oxide and water

Don’t have

Insoluble

Because Al2O3 highly exothermic lattice → strong ionic bonds w covalent character

pH of solution for reaction of aluminium oxide and water

pH 7

Equation of reaction of silicon oxide and water

Don’t have

Insoluble

Because numerous strong covalent bonds between atoms

pH of solution for reaction of aluminium oxide and water

pH 7

Equation for reaction of phosphorus oxide and water

P4O10(s) + 6H2O → 4H3PO4(aq)

pH of solution for reaction of phosphorus oxide and water

pH 2

Equation for reaction of sulfur oxide and water

SO3(g) + H2O(l) → H2SO4(aq)

pH of solution for reaction of sulfur oxide and water

pH 2

Equation for reaction of sodium oxide and acid

Na2O(s) + 2HCl(aq) → 2NaCl(aq) + H2O(l)

Equation for reaction of sodium hydroxide and acid

NaOH(aq) + HCl(aq) → NaCl(aq) + H2O(l)

Equation for reaction of aluminium oxide and acid

Al2O3(s) + 6HCl(aq) → 2AlCl3(aq) + 3H2O(l)

Equation for reaction of aluminium oxide and alkalis

Al2O3(s) + NaOH(aq) + 3H2O(l) → 2NaAl(OH)4(aq) [sodium aluminate]

Equation for reaction of aluminium hydroxide and acid

Al(OH)3(s) + 3HCl(aq) → AlCl3(aq) + 3H2O(l)

Equation for reaction of aluminium hydroxide and alkalis

Al(OH)3(s) + NaOH(aq) → NaAl(OH)4(aq) [sodium aluminate]

Equation of reaction of silicon oxide and alkalis

SiO2(s) + 2NaOH(conc.) → Na2SiO3(aq) [sodium silicate] + H2O(l)

Must be hot concentrated alkali

Equation for reaction of phosphorus oxide and alkalis

P4O10(s) + 12NaOH(aq) → 4Na3PO4(aq) + 6H2O(l)

Equation for reaction of sulfur oxide and alkalis

SO3(g) + 2NaOH(aq) → Na2SO4(aq) + H2O(l)

Equation for reaction of sodium chloride and water

NaCl(s) → Na^+(aq) + Cl^-(aq)

Without hydrolysis

pH of solution for reaction of sodium chloride and water

pH 7

Equation of reaction of magnesium chloride and water

MgCl2(s) + 6H2O(l) → [Mg(H2O)6]²^+(aq) + 2Cl^-(aq)

Appreciable hydrolysis

[Mg(H2O)6]²^+(aq) + H2O(l) ←/→ [Mg(H2O)5(OH)]^+(aq) + H3O^+(aq)

pH of solution for reaction of magnesium chloride and water

pH 6.5

Equation for reaction of aluminium chloride and water

AlCl3(s) + 6H2O(l) → [Al(H2O)6]³^+(aq) + 3Cl^-(aq)

Appreciable hydrolysis

[Al(H2O)6]³^+(aq) + H2O(l) ←/→ [Al(H2O)5(OH)]²^+(aq) + H3O^+(aq)

pH of solution for reaction of aluminium chloride and water

pH 3

Equation of reaction of silicon chloride and water

SiCl4(l) + 2H2O(l) → SiO2(s) + 4HCl(aq)

Complete hydrolysis

pH of solution for reaction of silicon chloride and water

pH 2

Equation of reaction of phosphorus chloride and water

PCl5(s) + 4H2O(l) → H3PO4(aq) + 5HCl(aq)

Complete hydrolysis

pH of solution for reaction of phosphorus chloride and water

pH 2

Complex ion for Al³^+

[Al(OH)4]^-

Equilibrium equation for Al³^+ and its complex ion

Al³^+(aq) + 4OH^-(aq) ←/→ [Al(OH)4]^-(aq)

Complex ion for Ag^+

[Ag(NH3)2]^+

Equilibrium equation for Ag^+ and its complex ion

Ag^+(aq) + 2NH3(aq) ←/→ [Ag(NH3)2]^+(aq)

Complex ion of Cu²^+

[Cu(NH3)4(H2O)2]²^+

Equilibrium equation for Cu²^+ and its complex ion

Cu²^+(aq) + 4NH3(aq) + 2H2O(aq) ←/→ [Cu(NH3)4(H2O)2]²^+(aq)

Complex ion of Cr³^+

[Cr(OH)6]³^-

Equilibrium equation for Cr³^+ and its complex ion

Cr³^+(aq) + 6OH^-(aq) ←/→ [Cr(OH)6]³^-(aq)

Complex ion of Zn²^+

[Zn(OH)4]²^-

[Zn(NH3)4]²^+

Equilibrium equation of Zn²^+ and its complex ions

Zn²^+(aq) + 4OH^-(aq) ←/→ [Zn(OH)4]²^-(aq)

Zn²^+(aq) + 4NH3(aq) ←/→ [Zn(NH3)4]²^+(aq)

Colour of Cr³^+(aq)

Green

Colour of Cr(OH)3(s)

Grey-green

Colour of [Cr(OH)6]³^-(aq)

Dark green

Colour of CrO4²^-(aq)

Yellow

Colour of Cr2O7²^-(aq)

Orange

Colour of Mn²^+(aq)

Pale pink

Colour of MnO2(s)

Black/brown

Colour of MnO4²^-(aq)

Green

Colour of MnO4^-(aq)

Purple

Colour of Fe²^+(aq)

Green

Colour of Fe³^+(aq)

Yellow

Colour of Fe(OH)2(s)

Dirty-green

Colour of Fe(OH)3(s)

Red-brown

Colour of [Fe(SCN)(H2O)5]²^+(aq)

Blood-red

Colour of Cu2O(s)

Red-brown

Colour of CuI(s), CuCl(s)

White

Colour of Cu²^+(aq)

Blue

Colour of Cu(OH)2(s)

Pale blue

Colour of [CuCl4]²^-(aq)

Yellow

Colour of [Cu(NH3)4(H2O)2]²^+(aq)

Dark blue

Colour of CuCO3(s)

Blue-green

Tollen’s reagent

[Ag(NH3)2]^+

Fehling’s solution

Cu²^+

Equation with Tollen’s reagent

RCHO + 2[Ag(NH3)2]^+ + 3OH^- → RCOO^- + 2Ag + 4NH3 + 2H2O

Equation with Fehling’s solution

RCHO + 2Cu²^+ + 5OH^- → RCOO^- + Cu2O + 3H2O

Equation of iodoform test on -CH(CH3)OH

RCH(CH3)OH + 6NaOH + 4I2 → CHI3 + RCO2^-Na^+ + 5NaI + 5H2O

Equation of iodoform test on -COCH3

RCOCH3 + 4NaOH + 3I2 → CHI3 + RCO2^-Na^+ + 3NaI + 3H2O

Define isotopes

Atoms of the same element with the same number of protons but has a different number of neutrons

Define cation

A positively charged species where number of protons is more than number of electrons

Define anion

A negatively charged species where number of protons is less than number of electron

Define isoelectronic

Two particles have the same number of electrons

Define orbital

A region of space where there is a high probability of locating an electron

Define ground state

An atom is said to be at ground state when all the electrons occupy orbitals of lowest possible energy configurations

Define degenerate

Orbitals have the same energy level

Define electronegativity

Refers to the electron-pulling power of an atom for the bonded pair of electrons in a covalent bond

Define ionic bonds

Strong electrostatic forces of attraction between oppositely charged ions

Define metallic bonds

Electrostatic forces of attraction between metallic cations and sea of delocalised electrons

Define covalent bonds

Strong electrostatic forces between two positively charged nuclei and the shared electrons between the atoms

Define polarisation

Refers to the distortion of the anionic electron cloud due to strong electron-attracting ability of the cation, resulting in a slight separation of charges

Define polar molecule

One which has a dipole moment

Define non-polar molecule

One which has no dipole moment

Define transition element

It is a d-block element whose atom has an incomplete d subshell or which can give rise to cations with an incomplete d subshell

Define catalyst

A substance that increases the rate of a reaction by providing an alternative reaction pathway with a lower activation energy, while remaining chemically unchanged at the end of reaction

Define heterogeneous catalyst

It is in a different physical phase from its reactants

Define homogeneous catalyst

It is in the same physical phase as its reactants

Define complex

A species consisting of a central metal atom or ion surrounded by ligands which are bonded to it through covalent dative bonds

Define coordination number

Refers to the number of dative bonds surrounding the central metal atom or ion

Define ligand

A molecule or anion that has at least a lone pair of electrons which can be used to form a covalent dative bond with a central metal atom or ion

Define a ligand-exchange reaction

Occurs when a stronger ligand replaces an existing ligand in the complex to form a more stable complex through a reversible system

Define relative atomic mass

The average mass of an atom of the element relative to 1/12 times the mass of carbon-12 atom

Define relative isotopic mass

The mass of an atom of the element relative to 1/12 times the mass a carbon-12 atom

Define relative molecule mass

The average mass of one molecule of a compound relative to 1/12 times the mass of a carbon-12 atom

Define relative formula mass

The average mass of one formula unit of the substance relative to 1/12 times the mass of a carbon-12 atom

Define mole

Defined as the amount of substance in 6.02 × 10²³ number of particles

Define partial pressure of a gas in a mixture

It is the pressure the gas would exert if it were to occupy the container alone

Define Dalton’s law of partial pressure

It states that in a mixture of non-reacting gases, the total pressure of the mixture is equal to the sum of the partial pressures of all the individual gases in the mixture

Define rate of reaction

It is the change in the amount or concentration of reactants or products per unit time

Define order of reaction

It is the power to which the concentration of a reactant is raised in an experimentally determined rate equation

Define rate constant

Is is the proportionality constant in the experimentally determined rate equation at a specific temperature