Chem mock

First ionisation energy

The first ionisation energy is the energy required to remove an electron from every atom in a mole of atomic gas, to produce a mole of unipositive gaseous ions.

Nth ionisation energy equation

Xⁿ⁻¹⁺ (g) → e⁻ + Xⁿ⁺

Ionisation energy ___ down a group

Decreases

Ionisation energy ___ across a period

Increases

Melting point ___ down group 2.

decreases

Why does magnesium have an anomalously low meting point?

it has a different crystal structure to the rest of group 2

Group 2 metals + water →

metal hydroxides + hydrogen

Reactivity ___ as you go down group 2

Increases

Exception to the group 2 reactivity trend

Beryllium

Solubility trend of group 2 hydroxides

Increases down group 2

Solubility trend of group 2 sulphates

decreases down group 2

Group 2 hydroxide that is sparingly soluble

Magnesium hydroxide

Completely insoluble group 2 sulphate

barium sulphate

Reactivity of group 2 metals ___ down the group

Increases

Group 2 metal + oxygen →

metal oxide

Group 2 metals + dilute acids →

metal sulphate + hydrogen gas

Group 2 salts solubility trend

Less soluble as you go down the group

Avogadro’s constant

6.02 x 10²³

Number of moles =

number of particles/Avogadro’s constant

Ideal gas equation =

pV = nRT

What is the value for R in the ideal gas equation?

8.314

What does p represent in the ideal gas equation?

Pressure in Pa

What does V represent in the ideal gas equation?

Volume in m³

What does n represent in the ideal gas equation?

Number of moles

What does T represent in the ideal gas equation?

Temperature in K

How to convert between °C and K?

°C + 273

How to convert between Pa and kPa?

Divide by 1000

How to convert between dm³ and m³?

Divide by 1000

Gas volume equation

n = volume in dm³/24

Equation for finding moles in the ideal gas equation?

n = pV/RT

Equation for finding pressure in the ideal gas equation?

p = nRT/V

Conc, mol, vol equation

c=n/v

Name two indicators used for acid/base titrations

Methyl orange and phenolphthalein

What is a standard solution?

A solution that has a precisely known concentration

Percentage yield =

(Actual yield/theoretical yield) x 100

% atom economy =

Molecular mass of desired product/sum of all molecular masses of products x 100

Reactions with ___ atom economies are less sustainable.

Low

A low atom economy means …

There is a lot of product wasted

Oxidation number of oxygen in a peroxide?

-1

Oxidation number of hydrogen in a metal hydride?

-1

Total electron configuration list

1s²2s²2p⁶3s²3p⁶4s²3d¹⁰4p⁶5s²4d¹⁰

A covalent bond is …

The strong electrostatic attraction between a shared pair of electrons and the nuclei of the bonded atoms.

Linear shape bond angle

180

What proportions are needed for linear shape?

two electron pairs

Trigonal planar bond angle

120

What proportions are needed for trigonal planar shape?

three bonding pairs

Tetrahedral bond angle

109\.5

What proportions are needed for tetrahedral shape?

4 bonding pairs

Trigonal pyramidal bond angle

107

What proportions are needed for trigonal pyramidal shape?

3 bonding pairs and 2 lone pairs

Non-linear bond angle

120

What proportions are need for non-linear shape?

2 bonding pairs and 2 lone pairs

Trigonal bipyramidal bond angle

3 = 120, 2 = 90

What proportions are needed for trigonal bipyramidal shape?

5 bonding pairs

Octahedral bond angle

90

What proportions are needed for octahedral shape?

6 bonding pairs

A higher number on the Pauling Scale means…

more electronegative

Electronegativity increases towards which element?

fluorine

Polar molecules have an overall ___

dipole

Difference in electronegativity values to be ionic

>2.0

Difference in electronegativity value to be polar

between 0.4 and 2.0

Difference in electronegativity values to be non-polar covalent.

What is a dipole?

A difference in charge between the two atoms caused by a shift in electron density in the bond.

Hydrogen bonds only happen when hydrogen is covalently bonded to ____

fluorine, nitrogen, and oxygen

Silver nitrate is used to test for ____?

Halide ions

Chloride ion colour in silver nitrate

White

Bromide ion colour in silver nitrate

Cream

Iodide ion colour in silver nitrate ?

Yellow

Which halide will dissolve in dilute ammonia?

Chloride ions

Which halide only dissolves in conc. ammonia?

Bromide ions

Which halide persists in concentrated ammonia?

Iodine

Order of ion tests

Test for carbonates → test for sulphates → test for halides

What reagent tests for sulphate ions?

Barium nitrate

Damp red litmus paper is used to test for ….. ?

Ammonium ions

Standard enthalpy change of combustion

Standard enthalpy change when of combustion when one mole of a compound is completely burned in oxygen under its standard conditions at RTP.

Enthalpy change of neutralisation

The enthalpy change when an acid and alkali react together to produce one mole of water.

Average mole enthalpy

Average bond enthalpy is the energy needed to break one mole of bonds in the gas phase, averaged over many different compounds,

Hess cycle of combustion

Hess cycle of formation

Way to remember arrow direction for hess cycle of combustion

Hot people go down

Standard conditions

298K and 101kPa

Catalyst for hydration of alkene into an alcohol

Acid catalyst (H₃PO₃/H₂SO₄)

\

Electrophilic addition catalyst

Ni

Why are are amines bases?

Because the one pair on the nitrogen atom forms a dative covalent bond and accepts the proton ( H+)

Bases are x acceptors and x donors

Proton, electron

What catalyst do you need for polyester hydrolysis?

Base

What catalyst do you need for polyamide hydrolysis?

Acid

Produce an aliphatic amine from a haloalkane

Haloalkane, ammonia (dissolved in ethanol)

Produce an aromatic amine by reducing an aromatic nitro compound

* make aromatic salt by heating nitro compound, tin metal, and conc. HCl under reflux
* Turn ammonium salt into an an aromatic amine by adding an alkali like NaOH

Functional group of an ester

Amino acid basic structure

Amine functional group

Amide functional group

Alkane to haloalkane reagents and conditions

Halogen and UV

Alkene to alkane reagents and conditions

H₂ and Ni

Alkene to haloalkane reagents and conditions

Hydrogen halide

Alkane to haloalkane reaction

Radical substitution

Alkene to alkane reaction

Hydrogenation

Alkene to haloalkane reaction

Halogenation

Alkene to alcohol reagents and conditions

Steam and H₃PO₄