Topic 5 Seperate Chemistry 1 (Complete)

Question 1

What are 4 properties of transition metals

Answer 1

High melting point
High density
Form coloured compounds
The metals and their compounds used as catalysts

Question 2

How do metals corrode

Answer 2

When they come in contact with air and water

Question 3

Rusting is for which metal

Answer 3

When iron corrodes it is called rusting

Question 4

What are some ways of preventing corrosion

Answer 4

Prevent rusting by coating iron with barrier
Painting
Oiling or greasing
Sacrificial protection

Question 5

What is sacrificial protection

Answer 5

Placing more reactive metal with the metal so the water and air react with the sacrificial metal instead of the metal your protecting

Question 6

What is electroplating

Answer 6

When you coat the surface of one metal with another metal using electrolysis

Question 7

How does electroplating work

Answer 7

Cathode is object your going to electroplate
Anode is the bar of another metal your going to use to electroplate the other
Electrolyte is solution containing metal ions of metal your using for the plating

Question 8

Explain what happens in terms of electrons during electroplating
Cathode is brass cup(what your electroplating)
Anode is bar of silver(what your using to electroplate)
Electrolyte solution of silver nitrate

Answer 8

Silver ions from electrolyte move to cathode and metal deposited on brass cup
Anode keeps the silver ions in the solution topped up

Question 9

Cathode Ag+ + e- —> Ag
Anode Ag —> Ag+ + e-

Question 10

What is an alloy

Answer 10

A combination of a different element added to a metal

Question 11

Why are alloys usually harder than pure metals

Answer 11

Pure metals all the ions can slide over each other because they are the same size
Alloys have different size atoms so the layers can’t slide over each other easily

Question 12

Why is iron not used on its own and alloyed with other metals to make alloyed steel

Answer 12

Iron on its own can rust but as steel is less likely to rust

Question 13

What is aluminium used for and how does its properties help

Answer 13

Aluminium used for aircraft as it has low density and is very strong

Question 14

What is copper used in and how does its properties help

Answer 14

Copper is used in wiring as it is a good conductor of electricity and is an unreactive metal

Question 15

Why is gold used in jewellery

Answer 15

Because it is unreactive and doesn’t conduct electricity

Question 16

What metals alloy to make magnalium and what is it used for

Answer 16

Magnesium and aluminium stronger than aluminium alone and has low density ,used in aircraft

Question 17

What metals is the alloy brass made of and what is it used for

Answer 17

Copper and zinc,used in musical instruments,door knobs,locks and taps

Question 18

What is the calculation for percentage yield

Answer 18

Actual yield/theoretical yield*100=percentage yield

Question 19

What 3 ways is the actual yield usually less then the theoretical yield

Answer 19

Practical losses
Incomplete reactions
Unwanted reactions/side reactions

Question 20

What is the calculation of atom economy

Answer 20

Mr of useful products/Mr of all products

Question 21

Why is it important to have a high atom economy

Answer 21

Lower atom economies waste resources very quickly and lots of waste materials are made

Question 22

Why is it good to have a high percentage yield

Answer 22

The higher percentage yield you have ,the more product you make

Question 23

How do you convert between cm(cubed) and dm(cubed)?

Answer 23

1000cm(3)=1dm(3)
Cm(3) to dm(3)
Divide by 1000

Question 24

Concentration=
Moles=
Volume=

Answer 24

Concentration(mol dm^3)=moles/volume
Moles=concentration*volume
Volume(dm^3)=moles/concentration

Question 25

It takes 25cm^3 of 0.100mol dm^3 sulfuric acid to neutralise 30.0 cm^3 of sodium hydroxide solution.The equation for this reaction is 2NaOH +H(2)SO(4) —->Na(2)SO(4) + 2H(2)O What is the acid and alkli in this reaction?

Answer 25

Acid -sulfuric acid Alkali - sodium hydroxide

Question 26

It takes 25cm^3 of 0.100mol dm^3 sulfuric acid to neutralise 30.0 cm^3 of sodium hydroxide solution.The equation for this reaction is 2NaOH +H(2)SO(4) —->Na(2)SO(4) + 2H(2)O How do you find the moles of sulfuric acid

Answer 26

Moles =concentration *volume 25/1000=0.025dm(3) 0.025*0.1=0.00250moles H(2)SO(4)

Question 27

2NaOH +H(2)SO(4) —->Na(2)SO(4) + 2H(2)O If there are 0.00250 moles of sulfuric acid how many moles are there of sodium hydroxide

Answer 27

1 mole of sulfuric acid reacts with 2 moles of sodium hydroxide 1:2 0.0025:0.0050 H(2)SO(4):2NaOH

Question 28

It takes 25cm^3 of 0.100mol dm^3 sulfuric acid to neutralise 30.0 cm^3 of sodium hydroxide solution.The equation for this reaction is 2NaOH +H(2)SO(4) —->Na(2)SO(4) + 2H(2)O

Question 29

We now know that the moles of sodium hydroxide is 0.0050 and the volume of it is 30cm^3 How do we found it’s concentration in mol dm^3

Answer 29

30cm^3/1000=0.03dm^3 Concentration =moles/volume Concentration=0.0050/0.03 Concentration=0.167 mol dm^3

Question 30

How do you convert 0.167 mol dm^3 of NaOH into g dm^3

Answer 30

Mol dm^3 * Mr = g dm^3 Mr of NaOH=23+16+1=40 40*0.167=6.7g dm^3

Question 31

What is molar volume /dm^3 mol

Answer 31

The volume occupied by one mole of a gas

Question 32

What is the molar volume of any gas at room temp and pressure

Answer 32

24dm^3 /24000cm^3

Question 33

Volume= Moles= Molar volume=

Answer 33

Volume=moles*molar volume Moles=volume/molar volume Molar volume=volume/moles

Question 34

How do you find the moles of a solid when given it’s formula Eg moles of 11.5g of Na

Answer 34

As of Na=23 11.5/23=0.5 moles

Question 35

What 2 things are made to make ammonia in Haber process

Answer 35

Nitrogen and hydrogen Ammonia used as a fertiliser

Question 36

What is the chemical equation for the Haber process

Answer 36

N + 3H 2 2

Question 37

Haber process is a reversible/irreversible reaction

Answer 37

Reversible

Question 38

Higher temp ,pressure and conc all do what to rate of attainment of equilibrium? What disadvantage may this have?

Answer 38

Increase rate at which equilibrium is obtained May decrease yield

Question 39

Catalysts do what to yield and rate of attainment of equilibrium

Answer 39

Increase rate of attainment of equilibrium and doesn’t affect yield

Question 40

What 2 things might companies consider about the about raw materials when making ammonia

Answer 40

Cost of raw materials and availability

Question 41

Why might pressures and temps very high may be difficult to obtain

Answer 41

May be dangerous and expensive

Question 42

How does higher temp help with increased rate of equilibrium attainment

Answer 42

Higher temp means more kinetic energy meaning more frequent collisions between particles to equilibrium is reached faster

Question 43

What 3 elements may ammonia fertilisers contain

Answer 43

Phosphorus Nitrogen Potassium

Question 44

What do fertilisers do

Answer 44

Gives plants nutrients they need if their is not enough and more to promote plant growth bigger and fastee

Question 45

What is ammonia reacted with to make it an acid and what is made

Answer 45

Reacted with nitric acid to make ammonium nitrate

Question 46

A chemical fuel cell produces a voltage until A)both reactants have been used up B)One of reactants have been used up C)Infinite unless it breaks

Answer 46

B

Question 47

In a hydrogen oxygen fuel cell ,hydrogen and oxygen are used to produce a voltage and what is the product

Answer 47

Water

Question 48

What are some advantages for hydrogen oxygen fuel cells

Answer 48

Very efficient (80%+) Less energy loss No greenhouse gases produced Energy produced directly f from reaction

Question 49

What are some disadvantage of hydrogen oxygen fuel cells

Answer 49

Very explosive so dangerous Gas takes up more space than liquid due to volume Hydrogen usually gathered from water vapour which usually burns fossil Fuels so not 100% clean