Seperate Chemistry 1 Flashcards by M3MES bigbrain

Transition metal properties

High melting / boiling point
Good heat / electric conductor 
High density 
Ductile 
Malleable 
Shiny
Hard
Colourful compounds 
Compounds are good catalysts

How well did you know this?

Not at all

Perfectly

Why alloys are stronger than pure metals

Allows contain different elements
Atoms of different elements have different sizes
Prevents layers of atoms from sliding over each other easily

How well did you know this?

Not at all

Perfectly

Properties of steel

Harder than iron
Stronger than iron (if carbon < 1%)
Less likely to corrode than iron

How well did you know this?

Not at all

Perfectly

How to make bronze

copper + tin

How well did you know this?

Not at all

Perfectly

Properties and uses of bronze

Harder than copper
Medals
Decorative ornaments
Statues

How well did you know this?

Not at all

Perfectly

How to make brass

copper + zinc

How well did you know this?

Not at all

Perfectly

Properties and uses of brass

more malleable than bronze
used where lower friction is needed
water taps
door fittings

How well did you know this?

Not at all

Perfectly

Properties and uses of gold alloys

Stronger than gold

Jewellery

How well did you know this?

Not at all

Perfectly

Properties and uses of aluminium alloys

Lower density than other metals and alloys

Aircraft manufacture

How well did you know this?

Not at all

Perfectly

How to make magnalium

aluminium + magnesium

How well did you know this?

Not at all

Perfectly

Properties and uses of magnalium

(low magnesium percentage)
stronger, lighter and corrodes less than aluminium
Aeroplane and car parts
(high magnesium percentage)
reactive but more stable than pure magnesium
Fireworks

How well did you know this?

Not at all

Perfectly

Corrosion definition

When something is slowly damaged or destroyed by a chemical process

How well did you know this?

Not at all

Perfectly

Rusting definition

Corrosion of iron

Only happens when iron is in contact with both oxygen and water

How well did you know this?

Not at all

Perfectly

How corrosion of metals is a redox reaction

Metal loses electrons (oxidised)

Oxygen gains electrons (reduced)

How well did you know this?

Not at all

Perfectly

How to prevent rusting / corrosion

Barrier e.g. painting/oiling/greasing (keeps water and oxygen out)
Sacrificial protection e.g. galvanising (when more reactive metal is placed with iron so oxygen and water reacts to it instead of wanted metal)

How well did you know this?

Not at all

Perfectly

Galvanisation definition

Coating iron objects with zinc to protect them from rusting

How well did you know this?

Not at all

Perfectly

Electroplating definition

Coating the surface of a metal with another metal using electrolysis

How well did you know this?

Not at all

Perfectly

Electroplating in preventing corrosion methods

Cathode = object to be electroplated
Anode = bar of metal used in plating
Solution = contains metal ions used in plating
Metal ions are deposited at cathode and anode “tops up” metal ions in solution

Titration purpose

How much acid is needed to neutralise a set amount of alkali (or vice versa)

Titration method

Measure out set volume of alkali using pipette
Add few drops of indicator with single colour change
Fill a burette with acid of known concentration
Use burette to slowly add acid to alkali, regularly swirling flask
Stop when indicator changes colour
Record volume of acid used to neutralise alkali

How to use titration results to work out concentration of reactants

Work out how many moles of reactant with given concentration are used
Use ratio of equation to find out moles of reactant with unknown concentration
Using given volume of reactant with unknown concentration and moles, work out its concentration

How to convert mol dm-3 to g dm-3

Multiply by RFM

Percentage yield equation

percentage yield = actual yield / theoretical yield x 100

Actual yield definition

mass of product actually made

Theoretical yield definition

mass of product made if all reactants were converted to products

Percentage yield method

Find RFM / RAM of reactant and product Work out moles of reactant Use ratio of equation to work out moles of product Work out theoretical yield by multiplying moles and RFM / RAM of product Divide actual yield by theoretical yield and multiply by 100 to get percentage yield

Why 100% yield is impossible

Incomplete reactions Practical losses e.g. transferring chemicals between containers Unwanted reactions

Atom economy definition

Percentage of reactants changed to useful products

Atom economy formula

total RFM of desired products / total RFM of total products x 100

Disadvantages of low atom economy

Uses up resources quickly Lots of waste Makes reactions unsustainable Resources may be expensive so not even profitable with low economy

Factors to consider in chemical industry

Percentage yield Rate of reaction Reversible reactions Atom economy

Factors to consider in an industrial process

Cost of extracting and refining raw materials | Energy costs to control the conditions

Haber process

N2 + 3H2 <=> 2NH3 (+heat)

Haber process conditions

Higher pressures favour forward reaction (more molecules on left side than right) Pressure is set as high as possible without impacting costs too much (200 atmospheres) Forward reaction is exothermic but more heat moves equilibrium position the wrong way Lower temperatures means lower rate of reaction so temperature is 450°C to compromise

How catalysts and conditions affect how quickly equilibrium is reached

By increasing rate of reaction, the rate at which equilibrium is reached is increased

Fertiliser facts

Contains nitrogen, phosphorus and potassium | Helps plants increase growth and life processes

Ammonia fertilisers benefits over traditional fertilisers

Can control compositions of chemicals Control how much is made Soluble so chemicals can dissolve down into soil to reach plants

Ammonium salts reaction

Example: | NH3 + HNO3 -> NH4O3

Molar volume equation

molar volume = gas volume / number of moles

Avogadro’s Law on molar volumes

same number of moles of different gases occupy the same volume 24dm3 per mol at room temperature

How fuel cells work

Type of chemical cell | Reacts fuel and oxygen to produce electrical energy efficiently

Reaction in hydrogen-oxygen fuel cells

hydrogen + oxygen -> water | 2H2 + O2 -> 2H2O

Advantages of hydrogen-oxygen fuel cells

Much more efficient (80% if heat produced is used) Electricity is generated directly in a fuel cell (fewer places to lose energy) No moving parts (no energy lost through friction) No conventional pollutants (only water and heat)

Disadvantages of fuel cells

Hydrogen gas is hard to store and is very explosive | Hydrogen is made from hydrocarbon or electrolysis of water, both involving the finite resource fossil fuels