Triple chem stuff i dont know

Giant covalent lattice- conduction of electricity

Cannot conduct. no ions or delocalised electrons to carry a charge

Giant covalent lattice- melting point

High due to strong covalent bonds throughout the structure which require lots of energy to break

Fullerene- melting point

Low due to weak intermolecular forces which

Giant covalent lattice- hard

due to strong covalent bonds throughout the structure which require lots of energy to break

Graphite- conduction of electricity

Can conduct due to delocalised electrons which can move through the structure and carry their charge

Graphite- melting point

High due to strong covalent bonds throughout the structure which requires lots of energy to break

Graphite- soft

and slippery because of the layers of atoms that can slide past each other due to the weak forces between them

Simple covalent molecules

low due to weak intermolecular forces requiring little energy to break

melting point analysis

melting point should be FIXED then its pure

baseline is drawn in pencil because

pencil is insoluble ( if in ink its soluble and would contaminate the results)

characteristics of compounds in the same homologous series

• same chemical properties

• same functional group

• each successive member of the series differs by CH2

Diamond is an element because

only made of 1 type of atom

Simple molecules- melting point

Low because of the weak intermolecular forces which do not require much energy to be overcome

All chlorides are soluble except

Silver and lead

All sulfates are soluble except

silver, lead barium and calcium

Crystallisation method

filter off the excess magnesium
heat the solution until crystals first start to form leave the solution to cool (and crystallise) pour/filter off excess liquid (to obtain crystals) leave (crystals) to dry

crystalisation why is the acid warmed

to speed up the rate of reaction

Crystallisation why use excess solid

so all acid is completely reacted, excess solid can be removed by filtration

all common: -,-,- are soluble

sodium, ammonium, potassium

All nitrates are

soluble

all carbonates and hydroxides are insoluble except

sodium, potassium, ammonium

solubility equation

mass of solute/mass of solvent x 100

Metals:

• conduct electricity

• metal oxides form basic hydroxides

Non- metals:

• do not conduct electricity

• non-metal oxides for acidic substances

a mole is…

the unit for the amount of a substance

concentration=

mol/vol

at room temp what volume does a gas occupy

24 dm³

covalent bond definition

the strong electrostatic attraction between the positive nuclei of the atoms and the shared pair of negative electrons

covalent bonds low melting and boiling points

have weak intermolecular forces which do not require lots of energy to overcome

simple covalent bonds can’t conduct electricity because

they have no charged particles ( no delocalised electrons or ions) to move and carry a charge

increasing length of hydrocarbons mean

• the bigger the molecules

• the stronger the intermolecular forces

• more energy required to overcome the intermolecular forces

allotropes are

different forms of the same element

giant covalent substances have a high melting and boiling point because

many strong covalent bonds throughout the structure which requires lots of energy to break

metallic bonding definition

the strong electrostatic attraction between positively charged metal ions and the negatively charged delocalised electrons

metals have high melting and boiling points

strong electrostatic forces between the delocalised electrons and metal ions are strong so needs lots of energy to overcome them

metals are malleable what does that mean

easy to bend and shape

metals are ductile what does that mean

can be drawn into wires

metals are malleable and ductile because

they have layers of positive ions and can slide over each other

metals are good conductors of electricity because

the delocalised electrons can move and carry their charge through the metal

trend in group 1

as you go down the group reactivity increases

• more shells

• weaker attraction

• easier to loose outer electron

• more reactive

trend in group 2

less reactive as you go down the group

• they only gain one electron

• easier for halogen to attract an electron with less shells because:

• has fewer shells so stronger attraction

• gains one more electron more readily

colour of fluorine:

yellow

colour of chlorine:

pale yellow and green gas

colour of bromine:

red-brown liquid

colour of iodine:

grey solid

potassium bromide with chlorine

orange brown

potassium iodide with chlorine

brown

potassium iodide with bromine

brown

nitrogen abundance in the air

78.1%

oxygen abundance in the air

21%

carbon dioxide abundance in the air

0.04%

argon abundance in the air

0.9%

oxygen abundance experiment: iron rust why is there not enough oxygen

was not enough iron or was not left long enough

hydrogen burning in oxygen

• burns with a pale blue flame

• the product is water

sulfer burning in oxygen

• burns with a brilliant blue flame

• gives a colourless and poisonous gas called sulfer dioxide)

properties of metal oxides

• ionic compounds

• usually basic- reacts with acids to form salts

• often insoluble in water and those that are form alkaline solutions

properties of non-metal oxides

• covalent compounds

• usually acidic- reacts with alkalis/bases to form salts

• often soluble in water to form acidic solutions

thermal decomposition of copper carbonate:

copper carbonate (green) → copper oxide (black) + carbon dioxide

what is an ore

a rock that contains enough of a metal compound in it to be worth extracting

aluminium uses:

aircraft bodies→ high strength to weight ratio

saucepans → very good conductor of heat and unreactive

electrical cables → very good conductor of electricity

food cans → non toxic and resistant to corrosion and acidic food

copper uses:

electrical wiring → good conductor and ductile

saucepans →good conductor, malleable and unreactive

hospital flooring → antimicrobial benefits

water pipes → unreactive and malleable

iron uses:

building materials → strong, malleable and ductile, relatively inexpensive

MILD STEEL

0.25% carbon → nails and bridges → strong and easy to shapes → rusts and is heavy

HIGH CARBON STEEL

0.6%-1.2% CARBON → cutting tools → hard and more brittle than mild steel

STAINLESS STEEL

20% CHROMIUM AND 10% NICKEL → cutlery and saucepans → resistant to corrosion

what is an alloy

a mixture of a metal and one or more elements, usually other metals or carbon

phenolphthalein

acid colourless base pink

methyl orange

acid red base yellow

acids in an aqueous solution are a

source of hydrogen ions

alkalis in an aqueous solution are a

source of hydroxide ions

an acid is a proton

donor

a base is a proton

acceptor

enthalpy change equation

Q/mol