Unit 5

Question 1

properties of transition metals

Answer 1

• high melting points
• high densities
• form colour compounds
• catalysts

Question 2

why alloys are stronger

Answer 2

different elements have different sized atoms which distorts the layers, so they cant slide

Question 3

steel

Answer 3

• carbon and pure iron
• harder and stronger
• doesn’t rust as easily

Question 4

corrosion

Answer 4

• redox reaction
• metals are oxidised
• oxygen is reduced

Question 5

rusting prevention

Answer 5

• coating iron with a barrier
• oiling/greasing
• painting

Question 6

sacrificial protection

Answer 6

placing a more reactive metal with iron so it corrodes instead

Question 7

galvanising

Answer 7

zinc is put with iron and loses electrons

Question 8

electroplating

Answer 8

cathode = object you're electroplating
anode = metal used 
electrolyte = metal ions of the metal you're plating

Question 9

percentage yield

Answer 9

actual yield/theoretical yield x 100

Question 10

factors affecting yield

Answer 10

• incomplete reactions
• practical losses
• unwanted reactions

Question 11

atom economy

Answer 11

total Mr of desired products / total Mr of all products x 100

Question 12

moles

Answer 12

vol/1000 x concentration

Question 13

concentration

Answer 13

moles x 1000/volume

Question 14

cm3 - dm3

Answer 14

/ 1000

Question 15

moldm-3 - gdm-3

Answer 15

x Mr

Question 16

conditions for the haber process

Answer 16

• 200 atmospheres
• 450 degrees celcius
• iron catalyst

Question 17

3 essential elements in fertilisrs

Answer 17

• nitrogen
• phosphorus
• potassium

Question 18

advantages of fuel cells

Answer 18

• more efficient
• no heat energy lost
• no pollutants

Question 19

fuel cell

Answer 19

type of chemical cell thats supplied with a fuel and oxygen and uses energy from the reaction to produce electricity