chemistry and Electrolysis p1

More reactive metals have

Faster rates of reaction.

As you go down the reactivity series,

Group numbers go up.

If hydrogen is present when you light a splint

It will go out with a squeaky pop

If oxygen is present when you light a splint

It will burn steadily

Metal + acid oxide >

Salt + hydrogen

1dm³

0.01cm³

Oxygen will displace substances in electrolysis if

It is more reactive

Metal + water >

Metal hydroxide + hydrogen

When metals react with water to produce hydrogen gas,

They fizz

Acetal bellow hydrogen in the reactivity series will not

React with dilute acids

If a metal is displacing another metal in a solution,

The solid metal can be ome covered in the dissolved metal as they switch places

Metals less reactive than oxygen=

Metals that don’t form oxides

Sights of displacement reactions:

Colour change, fizzing.

In a balanced equation for displacement, the only thing that changes is the

State symbol

Acid + metal carbonate>

Co2 and H2o

Displacement reaction equations can be split into

Oxidation and reduction

Copper occurs as mostly a sulphate because

It doesn’t react with oxygen

Heating iron ore with carbon produces carbon monoxide because

Carbon displaces iron in the iron oxide

Base

Anything that reacts with an acid to form a salt

Soluble base

Alkali

Acid + alkali really tons are radox because,

If a metal becomes a salt, it oxidises at gives electrons to a non metal, witch reduces.

Acid + alkali >

Salt + water

Soluble salts can be made by:

Reacting and acid with an insoluble reactant eg metal oxides, carbonates etc

Reactants to make soluble salts depen on

The salt required

Meals alone aren’t usually used to make soluble salts because

They produce flammable hudrogen

Electrolysis is connected to a

Dc supply

Electrolysis happens when water is acidification because

It can conduct electricity better

Half equations must:

Be balanced and have equal care on either side

Chlorine tends to

Bleach indicator strips

Oxygen will be produced at the anode, unless halides are present, in which case

The halides lose electrons and form halogens

Neutralisation

Adding correct amounts of H+ ( acids ) and OH- ( alkalis ) to get water.

Electrolysis separates ions, but doesn’t

Make them into neutral atoms.

When acids react with a base, you usually get water because

The base is usually alkali

When anions lose electrons to the anode,

They are transferred to the cathode.

Acid + metal hydroxide >

Salt + H20

Acid + metal oxide >

Salt + H2o

Acid +metal >

Metal salt + hydrogen

Native metals

Can be found naturally and don’t need to be extracted.

Non native

Can only be found as compounds and need to be extracted.

Metals more reactive than carbon

Potassium, lithium, calcium, magnesium, aluminium

More reactive than hydrogen

Zinc, iron

Elements less reactive than hydrogen

Copper, silver, gold

Elements that require electrolysis to be extracted:

Elements more reactive than carbon.

Elements that can be extracted throught melting with carbon:

Elements less reactive than carbon

Displacement:

When more reactive elements replace less reactive ones in a compound

NaCl

Sodium chloride

MgBr2

Magnesium bromide

Potassium oxide

K2O

Aluminium chloride

AlCl3

Aluminium oxide

Al2O3

Ph7

Neutral/water

On the right of 7:

Alkalie

On the left of 7:

Acid

Lower ph number=

Stronger substance

Alkalie

A substance that breaks down to give OH- ions

Acid

Substances that break down to give H+ ions

Acids + alkalis

Neutral water

The more hydrogen in a substance,

The more acid/less alkali it becomes

Salt equation with metals:

Acid+metal>salt+hydrogen gas

Salt name formula

Metal+ending based on acid

Sodium chloride=

HCl

Sodium nitrate=

HNO3

Sodium sulphate

H2So4

Salt equation with oxides:

Oxide+acid>salt+water

Molecular formula

Number of each element atoms in an atomic structure

Concentration

How much acid is dissolved per litre(mol dm-3)

Strong acid

An acid that releases all of its hydrogen in water - fully ionising

Weak acid

An acid that releases some of its hydrogen in water - partially ionising.

HA

Any acid

Ph number going up by 1 means

Concentration reduces by 10.

Electrolysis

The process of using energy supplied by electricity to split apart ionic compounds.

Mass symbol

(Mr)

PANIC

Positive anode negative is cathode

Cat ions (+) go to

The cathode (-)

An ions (-) go to

The andode (+)

Electrolyte

Any ionic compound dissolved in water or melted

Electrolysis can only take place in molten or dissolved compounds because

the ions are spread out and can move

The side of the circuit with anodes=

Left (big line of the cell)

The sife of the circuit with cathode=

Right (small side of cell)

In electrolysis, negative ions

loose electrons to the anode

In electrolysis, Positive ions

Get electrons from the cathode

from molten ionic compounds

You will get the metal

Why do you get hydrogen wneh ionic compounds dissolved in water are group 1 or 2?

Because the metal displaces the hydrogen in the water it’s dissolved in.

Ore

A metal containing compound found in rocks.

Oxidation

Adding oxygen

Reduction

Removing oxygen

Metal + oxygen >

Metal oxide

If ionic compounds are dissolved in water,

You will get hydrogen gas if the metal is group one or two.

Why do you get hydrogen gas

Because metals more reactive than hydrogen displace the hydrogen in water.

Ore

A metal containing compound found in rocks

Oxidation

Adding oxygen

Reduction

Removing oxygen

OILRIG

Oxidation is loss of electrons reduction is gain of electrons.

Electrons go with reactants in an equation when

They are gained