All of Chemistry

Formula for Sulfuric acid and Hydrochloric acid

H2SO4

HCl

Formula for Nitric acid and Phosphoric acid

HNO3

H3PO4

Acid + Base-->

Salt + Water

What is an acid

A substance that acts as a proton donor in a solution

What is a base

A substance that acts a a proton reciever in a solution

What is a neutralisation reaction?

The reaction between an acid and a base which always involves a proton transfer from the acid to the base

Ionic Dissociation of HCl

HCl--> H+ + Cl-

What is the ionic equation for neutralisation

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

In Ionic equations which substances can be split into sepeate ions and which can be cancelled out.

Every substance that is dissolved in water (aq)

Spectator ions can be cancelled out where the ions appear on both sides

Steps to produce an insoluble salt from two soluble salts

Mix- the two soluble salts

Filter- with filter paper

Wash- with distilled water

Dry- By patting dry with filter paper or leaving in a dry oven

Why is the wash step necessary in insoluble salt prep?

Why use distilled not tap water?

Removes Soluble Impurities

Tap contains dissolved ions, distilled prevents unwanted contamination, and side reactions

What colour does Universal indicator turn in an acid, neutral and base solution

Red

Green

Purple

What colour does Litmus turn in an acid, neutral and base solution

Acid: Red

Neutral: Purple

Base: Blue

What colour does Methyl Orange turn in an acid, neutral and base solution

Red

Orange

Yellow

What colour does Phenolphthalein turn in an acid, neutral and base solution

Colourless

Pale pink

Deep pink

What are alkalis

Bases that are soluble in water

experiment for a soluble salt

Heat- the acid

Excess- add the insoluble reactant in excess

Filter- To remove the excess

Evaporate- 1/2 solution

Dry- Pat dry with filter paper/ warm dry oven

Metal+Acid-->

Salt+hydrogen

Metal+Carbonate-->

Salt + Carbon Dioxide + Water

Metal + Hydrogencarbonate -->

Salt + Carbon dioxide + Water

Can Hydroxides oxides and ammonia act as bases

Yes

What is a mole?

Amount of a substance

What is Avogadro's number

6.022 x 10^23

What is relative atomic mass (Ar)

The mass of an atom of an element when compared to 1/12 of the mass of a carbon-12 atom. No units

What is relative formula mass (Mr)

The mass of a molecule or compount when compared to 1/12 the mass of a carbon-12 atom. No units

What is Molar Mass (M)

The mass of one mole of a substance. Units g/mol

How to calculate the Molar Mass of H2O

H20= 1*2+16=18g/mol

Formula for Moles

How to calculate how many atoms of 1mol of CO2

Describe the experiment to determine the empirical formula of copper(II) oxide via reduction

Weigh: Record mass of empty test tube with hole + bung.

Add & Weigh: Add copper(II) oxide, re-weigh to find initial mass of CuO

Purge & Ignite: Pass methane gas to flush out air; light the excess methane emerging from the hole.

Heat: Heat strongly until black powder turns fully pink/brown (copper metal).

Cool: Turn off heat, keep methane flowing until cool.

Final Weight: Re-weigh tube, bung, and remaining copper.

What physical observation indicates that copper(II) oxide has been reduced?

Black solid (CuO) turns to Orange (Cu)

Why is it necessary to continue the flow of methane until the apparatus is cool?

To cool the tube and to stop O2 getting back into the test tube, preventing the formation of CuO

Why might this experiment result in a formula with:

a) Too much oxygen?

b) Too much copper ?

Too much O: Incomplete reduction (black CuO) wasn't heated long enough to fully react).

b) Too much Cu: Copper solid blown out of the tube.

What is empirical formula

the simplest whole number ration between the number of atoms of each element in its chemical formula

What are the two ways you can calculate empirical formula

With masses of each element of percentages of each element

If the empirical formula is not a whole number ratio what must you do

Find a multiple that makes both numbers whole numbers

Describe the experiment to find the empirical formula of magnesium oxide via combustion.

Weigh: Record the mass of a crucible with its lid.

Prep & Weigh: Clean 10g magnesium ribbon, coil it into the crucible, and re-weigh with the lid.

Heat & Lift: Heat strongly with a roaring flame. Periodically lift the lid briefly to allow oxygen in while preventing white smoke from escaping.

Constant Mass: Heat to constant mass, then allow to cool.

Final Weight: Re-weigh mass of crucible

What is observed when magnesium burns, and what key safety precaution must be taken during finding the EP for MgO?

White gas

Red Glow

Why is it necessary to lift the lid of the crucible when heating MgO for the EP experiment

So Oxygen can get in

Why do we wish to prevent the white smoke leaving the crucible?

To try not to let any MgO out, as losing it leads to a lower mass skewing the EP

Explain why the MgO combustion experiment rarely produces the right EP, why may it produce a formula with too much Mg

As the lid wasn't lifted for long enough

Stopped heating too early

Experiment to calculate the formula of hydrated Copper Sulfate

Weigh: Record mass of empty crucible or evaporating dish.

Add & Weigh: Add blue hydrated copper sulfate crystals, re-weigh to find mass of hydrate.

Heat Gently: Heat gently with a Bunsen burner until the blue crystals turn completely into white anhydrous powder.

Constant Mass: Cool and re-weigh; repeat heating and weighing until mass remains constant.

Final Mass: Record the final mass of the crucible + white anhydrous Copper Sulfate

What is the molecular formula

The Real Chemical formula of a substance

How to convert EF to MF

Then times the empirical formula compound by the multiple

What two pieces of info are needed to calculate water of hydration

The mass of the anhydrous salt

The mass of the water

What is the formula for % by mass

steps to find mass of a substance from the mass of another substance

Balanced equation

Convert mass to moles of known mass

Convert between moles using the molar ratio in the balanced equation

Convert moles to mass

Formula for moles of a gas

How many cm3 if one dm3

1000

Formula for percentage yield

Formula for Molar Concentration

What is the molar volume of a gas

24 dm3 or 24000cm3

How are elements arranged in the periodic table

In order of atomic number

What are the vertical columns on the periodic table called?

Groups.

What is common about elements in the same group

They have the same number of electrons in their outer shell, so often react in a similar way.

What re the horizontal rows on the periodic table called

Periods

What does the period number indicate

The number of shells of electrons

Observations, inferences and other info

Lithium reacting with Water

What colour does UI go

Fizzing- Gas produced- H2

Moves on surface- Density less than water

Metal gets smaller- Reacting away

Other info: UI goes purple- OH- ions in water- LiOH formed

Observations, inferences and other info

Sodium reacting with Water

What colour does UI go

Fizzing- Gas produced- H2

Moves on surface- Density less than water

Metal gets smaller- Reacting away

Melts into a ball- low melting point

Other info: UI goes purple- But makes NaOH

Observations, inferences and other info

Potassium reacting with Water

What colour does UI go

Fizzing- Gas produced- H2

Moves on surface- Density less than water

Metal gets smaller- Reacting away

Melts into a ball- low melting point

Lilac flame- H2 is burning

Other info: Ui goes purple-

How are the atoms in Group 1 metals bonded

Atoms lose their outer electron

Regular lattice of positive ions held together by delocalised electrons

Hardness and strength

Melting points

Density

Of G1 metals

Soft/Weak

Low

Low

Reactivity

Formation of ions

Of G1 metals

High

+1

What is the state of all the halogens at room temp

Flourine: Gas

Chlorine: Gas

Bromine: Liquid

Iodine: Solid

Astetane:Solid

What is the colour of Flourine normally and in water

Pale yellow

In water: Colourless

What is the colour of Chlorine normally and in water

Yellowish green

In Water: Very pale yellow

What is the colour of Bromine normally and in water

Red-brown

In water: Orange

What is the colour of Iodine normally and in water

Grey

In water: Brown

What is the colour of Ascetene

Black

How to determine the order of reactivity using displacement reactions with halogens

A more reactive halogen will displace a less reactive halogen from an aqueous solution of its halide

How does the reaction of Chlorine with Potassium bromide and potassium iodide show that Chlorine is more reactive

with Bromide the solution turns orange so Br2 is made (displaced)

With Iodide the solution turns brown so I2 made (displaced)

Trend in reactivity descending group 1 and 7

1: Increases

7: Decreases

Explain the trend in reactivity descending group 1

Reactivity increases

Atoms get bigger descending the group

Outer electron becomes further away from the nucleus

The force of attration is weaker between the outermost electron and the nucleus

Becomes easier to loce the outer electron

Explain the trend in reactivity descending group 7

Reactivity decreases

Atoms get bigger

Outer electron is further away from the nucleus

Force of attraction is weaker between outermost electrons and nucleus

Harder to gain an electron

Common uses of Halogens

To kill bacteria

Large Scale diinfection of water sources (chlorine)

Iodine is antiseptic

Key properties of Noble Gases

They exist as single atoms not molecules

Virtually no bonding between the atoms of a noble gas so they have v low melting and boiling points

What happens to the strength between the atoms as the atoms get bigger in the noble gases

Interatomic forces increase, due to increasing number of electrons.

So melting and boiling points increase descending the group

How reactive are the noble gases and why

Very unreactive as they already contain a full outer-shell of electrons so they don't need to gain, lose, or share electrons in chemical reactions

General physical properties for transition metals

Shiny, grey

High Melting Point

Strong

Hard

High malleability

Important uses of transition metals

As catalysts to speed up the rate of chemical reactions in industrial processes.

Used to make alloys

Where is the Non-Metal zig zag line

Above Al

What is an allotrope

Different forms of the same element dur to different bonding and structure

What is a covalent bond

The electrostatic forces of attraction between a shared pair of electrons and the atoms nuclei

How strong are Covalent bonds

Very strong

Diamond

Structure

Bonding

Key property

Structure: giant covalent lattice

Each C connected to 4 others

Bonding: Covalent in 3D- V strong

Key Property: Very hard and strong, high melting point

3D network of v strong bonds requires lots of energy to break

Graphite

Structure

Bonding

Key property

Giant covalnet lattice

Each C atom connected to 3 others

Bonding: Covalent bonds in 2D layers. Weaker bonding between layers

Key property: can conduct electricity- as has delocalised electrons that can move and carry charge

Soft- layers can slide over each other

C60

Structure

Bonding

Key property

Structure: Molecular

Bonding: Covalent bonds in each molecule

Weak intermolecular forces between molecules.

Key property: Low melting point: weak intermolecular forces require little energy to break

Experiment for thermal decomposition of limestone and observations

Heating marble chips CaCO3 strongly to break them down into calcium oxide and carbon dioxide gas

Marble chip glows with bright white light (limelight)

Reaction of Calcium Oxide with Water and observations

dding water to quicklime CaO to produce calcium hydroxide Ca(OH)2, creating an alkaline solution.

Steam produced (highly exothermic); Universal Indicator turns purple (basic)

Limewater and Carbon Dioxide Test

Bubbling carbon dioxide gas CO2 through limewater Ca(OH)2 to form an insoluble solid precipitate.

Limewater turns cloudy/milky

What do increasing amounts of CO2 in the atmosphere may contribute to

Climate Change (as it is a greenhouse gas)

Green powder CuCO3 turns into a black powder CuO; gas produced turns limewater cloudy CO2.

What is a hydrocarbon

A molecule containing only carbon and hydrogen atoms

If an alkane molecule gets lager and heavier what happens to the melting and boiling point

Increases. As the intermolecular forces between the molecules become stronger as the molecules become larger so more energy is required to separate the molecules

Are larger lakanes more or less volatile than smaller ones

Less volatile

General formula for the alkanes

CnH2n+2

What is an isomer

A compound with the same molecular formula but a different structural formula

Properties of a homologous series

Same general formula

Similar chemical properties (react similarly)

Each member differes from the next by a CH2 unit

Same functional group

Trend in physical properties eg boiling points

What differens alkanes from alkenes

Alkenes have a double bond

General formula for the alkenes

CnH2n