Chemistry Unit 1/2

Whats an acid

A proton donor

Hydrogencarbonate

HCO3-

Manganate(VII)

MnO4-

Hydrogensulfate

HSO4-

Nitrate

NO3-

Copper

CU+

Silver

Ag+

Ammonium

NH4+

Sulphate

SO42-

Sulphite

SO32-

Carbonate

CO32-

Sulphide

S2-

Dichromate

Cr2O72-

Lead(ii)

Pb2+

Tin(ii)

Sn2+

Copper(ii)

Cu2+

Iron(ii)

Fe2+

Zinc

Zn2+

Phosphate

PO43-

Iron(iii)

Fe3+

Lead(iv)

Pb4+

Tin(iv)

Sn4+

Nitric Acid

HNO3

Sulphuric Acid

H2SO4

Phosphoric acid

H3PO4

Ethanoic Acid

CH3COOH

Ammonia

NH3

Potassium Hydroxide

KOH

What is a base

A proton acceptor

What is an alkali

A water-soluble base that releases hydroxide ions (OH-) when dissolved.

what is a salt

A compound formed from when the H+ ion from an acid is replaced my a metal ion or another positive ion

Whats a strong acid

An acid that completely dissociates in solution releasing all of its H+ ions

Whats a weak acid

An acid that partially dissociates in solution releasing some of its H+ ions

Whats a strong base

A base that completely dissociates in solution, releasing all its OH- ions

Whats a weak base

A base that partially dissociates in solution releasing some of its OH- ions

Name 4 common bases

Metal oxides, metal hydroxides, metal carbonates and ammonia

Name three strong acids

Hydrochloric acid, sulfuric acid and nitric acid.

Name three alkalis

Sodium hydroxide, potassium hydroxide, and ammonium hydroxide.

Whats the equation for a reaction of an acid with an alkali

Acid + Alkali = Salt + Water

Whats the ionic equation for acid reacting with an alkali

H+(aq) + OH-(aq) = H2O(l)

Whats the ionic equation for a weak acid reacting with an alkali

HA(aq) + OH⁻(aq) → A⁻(aq) + H₂O(l)

Whats the reaction of an acid with a base

Acid + Base = Salt + Water

Whats the ionic equation for the reaction between an acid and a base

2H+ + O2- = H20

what would you observe in a reaction with an acid and a base

Fizzing and the solid disolving

Whats the equation between an acid and a carbonate

Acid + Carbonate = Salt + Water + Carbon Dioxide

Whats the ionic equation between an acid and a carbonate

2H+ + CO32- = H2O + CO2

Whats the equation of a reaction between an acid and a metal

Acid + Metal→ Salt + Hydrogen

Whats the ionic equation of a reaction between acid and metal

H+ + Metal → Metal Ion + H2

What would you see in a reaction between an acid and a metal

Fizzing when the metal dissolves

whats the equation when acids are neutralised by aqueous ammonia

Acid + NH3 → Ammonium Salt

whats the only product in a reaction between ammonia and acid

Ammonium salt

In the reaction between ammonia and an acid what happens to form the ammonium ion

The ammonia accepts a proton from the acid

Whats a mole

amount of any substance with as many particles as carbon atoms in exactly 12g of carbon 12

whats avagadro’s constant

6.02 ×10²³

equation to figure out moles/mass/mr

moles = mass / mr

what do you do to calculate the number of molecules.

moles = mass / mr and times moles by avogadros constant

whats the empirical formula

the simplest whole number of atoms in each element in a compound

How do you calculate the empirical formula

mass / mr to find moles
divide the moles by the smallest number of moles to find the ratio
With that ratio you write the element with the amount from the ratio

whats the molecular formula

the actual number of atoms of each molecule in a compound

How to calculate the molecular mass

Calculate the empirical formula and add the mr of all elements together
then divide by the molecular mass given to you by the mr
times each element from the empirical formula by the number you just got

what does hydrated mean

A compound that contains water molecules within its crystal structure.

What does anhydrous mean

A substance that does not contain water molecules within its crystal structure.

What is water crystallisation

water molecules that from the crystalline structure of a compound

What is assumption 1 to be made when doing water crystallisation (short)

water has been lost

whats the second assumption

no further decomposition

whats the conversion for volume m—>dm—>cm

M³ to Dm³ = x1000

Dm³ to Cm³ = x1000

What is ionic bonding

Electrostatic attraction between positive and negative ions (metal and non metal)

How are ionic bonds formed

The transfer of an electron from a metal to a non metal to form ionswhich then attract each other due to opposite charges.

what diagram represents ionic bonding

dot and cross

what structures do giant ionic lattices form

Giant ionic lattices

Properties of ionic compounds

solid at room temp. they have a high melting and boiling point as a large amount of energy is needed to overcome the electrostatic forces of attraction between oppositely charged ions

Explain conductivity within ionic bonds

In a solid state they cannot conduct electricity as they are in a fixed position in the lattice but when melted or dissolved in water, they can conduct electricity as the ions are free to move.

Why are ionic compounds soluble in polar solvents

polar water molecules are attracted to the positive and negative ions in the ionic compound. The giant ionic lattice breaks down

Explain
melting point
conductivity
solubility
of magnesium oxide

it is a giant ionic structure and has a high melting point due to lots of energy being required to overcome electrostatic forces of attraction between oppositely charged electrons. It conducts electricity when molten due to ions being free to move and carry a charge yet when solid they cannot move. Its soluble in polar solvents because the bonds are attracted to water molecules so begin to dissolve

What is covalent bonding

strong electrostatic attraction between a shared pair of electrons between non metals

What happens in covalent bonding

each atom donates a valence electron to the bond, it fills up the outermost energy shell to achieve a full outershell

What are the examples to the octet rule

Be and B- they do not have enough unpaired electrons to reach a noble gas configuration. Expansion: as you go further down one of the bonding atoms may finish with more than 8 electrons in the outer shell

What elements form Giant covalent structures

Elements from group 4

Describe the 3 properties of Diamond

1) high melting point so needs a lot of energy to overcome the covalent bonds 2) it is a bad conductor because all 4 atoms are bonded to 4 carbon atoms so has no delocalised electron 3) Insoluble in water as the bonds are too strong to be broken

Describe the 4 properties of graphite

1) it has a high melting point as alot of energy is needed to overcome the covalent bonds 2) it is a good conductor as it has a delocalised electron 3) insoluble in water as the bonds are too strong to be broken 4) layers can slide over each other, making it a lubricant.

Describe 2 properties of graphene

1) each carbon atom is bonded to 3 other carbon atoms so has a delocalised electron yet moves quicker so is the best conductor 2)Its one sheet joined in a hexagonal shape and is one atom thick

What are simple molecular structures made up of

molecules held together by weak induced dipole-dipole forces

What are the physical properties of simple molecular substances

low melting point as the weak induced dipole-dipole forces need little energy to overcome. They cannot conduct electricity because all electrons are involved in bonding

what is dative bonding

sharing of a pair of electrons where one atom donates both electrons to a bond.

What is metallic bonding

Electrostatic force of attraction between a lattice of positively charged ions and a sea of delocalised electrons between metal atoms

whats the structure of metallic bonding described as

a giant metallic lattice

What are the properties of metals

1) high melting and boiling points 2) excellent conductors of electricity

How many shapes of molecules are there

6

Whats the shapes of molecules determined by

Number and type of electron pairs

Whats the electron pair repulsion theory

if they are negatively charged the repel eachother. Electrons exist in pairs (lone or bonding). A lone pair repels more than a bonded pair

BeCl₂ shape/angle

Linear/180_⁰

Whats the sentence for Linear

2 bonding pairs. 0 lone pairs. bonding pairs repel equally

BF₃ shape/angle

Trigonal planar/120_⁰

whats the sentence for trigonal planar

3 bonding pairs. 0 lone pairs. Bonding pairs repel equally

NH_{4 ⁺} shape/angle

Tetrahedral/109.5°

whats the sentence for tetrahedral

4 bonding pairs. 0 lone pairs. Bonding pairs repel equally

SF₆ shape/angle

Octahedral/90°

whats the sentence for octahedral

6 bonding pairs. 0 lone pairs. Bonding pairs repel equally

NH₃ shape/angle

pyramidal/107°