Separate Chemistry 1

Question 1

What are the properties of transition metals

Answer 1

hard
strong
shiny
malleable
good conductors
high boiling points (except mercury)
high densities
good catalysts

Question 2

Examples of uses of transition metals

Answer 2

Gold is used in jewellery - shiny and malleable
Copper is used for water pipes - malleable and corrosion resistant (also used for electrical wiring as it is a good electrical conductor)

Question 3

How do transition metal compounds look

Answer 3

Very colourful

Question 4

What are alloys

Answer 4

A mixture of metals in an unfixed ratio

Question 5

Why are alloys stronger

Answer 5

The differently sized particles prevent the layers from sliding over each other easily

Question 6

Examples of uses of alloys

Answer 6

Steel - carbon + iron - less likely to rust
Brass - Copper + Zinc - more malleable used in water taps
Aluminium alloys - used in aircrafts

Question 7

What kind of reaction is rusting of iron

Answer 7

Redox
Oxygen is reduced
Iron is oxidised

Question 8

How to prevent rusting

Answer 8

Painting
Oiling
Greasing
Galvanising (Zinc)

Question 9

What is electroplating

Answer 9

Applying a metal coating to an object
Use electrolysis
Object as cathode

Question 10

What do titrations allow you to do

Answer 10

Find out exactly how much acid is required to neutralise a given quantity of alkali

Question 11

How to calculate % yield

Answer 11

Actual yield / theoretical max yield (x 100)

Question 12

Why do you almost never get 100% yield

Answer 12

Incomplete reactions
Unwanted side reactions
Practical losses
Energy lost to surroundings

Question 13

What is atom economy

Answer 13

The % of reactants changed to useful products

Question 14

How to calculate atom economy

Answer 14

Total Mr of desired product / Total Mr of all products (x100)

Question 15

Why is high atom economy good

Answer 15

Less waste products
Less raw materials needed for a given amount of product

Question 16

Why are the conditions for the Haber process used

Answer 16

High pressure is ideal but too high is to expensive
Lower temp. is ideal but would be a too slow rate of reaction
Catalyst used to make the reaction faster

Question 17

Where are the gases for the Haber process obtained from

Answer 17

Nitrogen - Air
Hydrogen - crude oil or natural gas

Question 18

What are the problems with using ammonia as a fertiliser

Answer 18

Can damage crops on it’s own
Toxic gas
Can evaporate away

However, when combined with other chemicals it can be used to supply nutrients (nitrogen, phosphorus and potassium)

Question 19

How to calculate molar volume

Answer 19

gas volume / number of moles

Question 20

What do fuel cells use to produce energy

Answer 20

Fuel and oxygen

Question 21

What do hydrogen-oxygen fuel cells use as fuel

Answer 21

Hydrogen

Question 22

Advantages of Hydrogen-Oxygen fuel cells

Answer 22

Very efficient
Less stages so less energy lost as heat and no moving parts so less energy lose through friction
No conventional pollutants

However

Hydrogen takes up more space to store

Hydrogen is highly explosive

The production of the fuel often involves fossil fuels