Separate Chemistry 2

Question 1

What colour flame does Lithium have

Answer 1

Crimson

Question 2

What colour flame does Sodium have

Answer 2

Yellow

Question 3

What colour flame does Potassium have

Answer 3

Lilac

Question 4

What colour flame does Calcium have

Answer 4

brick red/ orangey

Question 5

What colour flame Copper have

Answer 5

blue-green

Question 6

How to carry out a flame test

Answer 6

Clean a nichrome wire loop by dipping it in HCl

Then dip into metal compound and place loop into the clear blue part of a bunsen flame

Question 7

What colour precipitate does aluminium form

Answer 7

White
But dissolves with excess NaOH

Question 7

How to test for metal ions that form precipitates

Answer 7

Add NaOH

Question 8

What colour precipitate does Calcium form

Answer 8

White

Question 9

What colour precipitate does Copper (2) form

Answer 9

Blue

Question 10

What colour precipitate does Iron (2) form

Answer 10

Green

Question 11

What colour precipitate does Iron (3) form

Answer 11

Brown

Question 12

How to test for ammonia

Answer 12

add NaOH solution

If present then damp red litmus will go blue

Question 13

How to test for halide ions

Answer 13

Nitric acid and then Silver Nitrate solution

Question 14

What colour precipitates do the halides form when tested

Answer 14

Chloride - white
Bromide - cream
Iodide - yellow

Question 15

How to test for carbonates

Answer 15

Add dilute acid
Then use CO2 test

Question 16

How to test for sulfate ions

Answer 16

HCl and Barium Chloride

Question 17

What colour precipitate will a sulphate form

Answer 17

White

Question 18

What does flame photometry allow us to do

Answer 18

Identify ions in a mixture or in a dilute solution

Question 19

How is it carried out
(flame photometry)

Answer 19

A sample is placed in a flame

The electrons are excited and as they drop back down to their original energy level the emit energy in the form of light

This passes through a spectroscope a a line spectrum is produced

Question 20

What is flame photometry useful for

Answer 20

Concentration of ions in solution
Intensity of light
Intensity of solution

Question 21

What are alkanes

Answer 21

Saturated hydrocarbons
Formula CnH2n+2

Question 22

What are alkenes

Answer 22

Unsaturated hydrocarbons
Formula CnH2n

Question 23

Test for alkene

Answer 23

Bromine water
Decolourise orange to colourless

Question 24

What are addition polymers

Answer 24

Polymers made from unsaturated monomers (alkenes)

Question 25

Uses of polymers

Answer 25

Poly(ethene) - Flexible, electrical insulator, cheap - used in plastic bags, bottles and wire insulation Poly(propene) - flexible, strong, touch, mouldable - crates, furniture, ropes Poly(chloroethene) (PVC) - tough, cheap - window frames, water pipes Poly(tetrafluoroethene) - unreactive, tough, non-stick - non-stick pans, waterproof clothing

Question 26

What type of monomer does polymerisation reactions involve

Answer 26

2 different types of monomer

Question 27

What are polymers made from

Answer 27

Crude oil

Question 28

Pros and cons of burning polymers

Answer 28

Pros: Energy released can be used for electricity Reduces volume of waste Cons: CO2 is made Toxic gases are also made

Question 29

Pros and cons of landfill

Answer 29

Pros: Cheap Easy No need to sort waste Cons: Destroys environment Waste is dangerous to animals Eyesore

Question 30

Pros and cons of recycling

Answer 30

Pros: Conserves a vital raw material (crude oil) Less waste to landfill Cons: Sorting plastics is time consuming Expensive

Question 31

What is the general formula of an alcohol

Answer 31

CnH2n+1OH

Question 32

What happens to alcohols to form carboxylic acids

Answer 32

Oxidised

Question 32

What happens if you meet a mixture of an alcohol and an acid catalyst

Answer 32

An alkene and water are formed This is called a dehydration reaction

Question 33

How are carboxylic acids similar to normal acids

Answer 33

React with carbonates to form CO2, salt and water Can partially ionise in solutions

Question 34

What is the general formula for Carboxylic acids

Answer 34

Cn-1H2n-1COOH

Question 35

What is a substitution reaction

Answer 35

Where a H gets substituted by another atom eg. Bromine This must happen under UV Eg CH4 + Br2 --> CH3Br + HBr

Question 36

What is an addition reaction

Answer 36

When an alkene reacts with a halogen The double bonds is broken and the halogen goes onto the 2 Cs with the double bond eg. C2H4 + Br2 --> C2H4Br

Question 37

Equation for breakdown of glucose

Answer 37

C6H12O6 --> 2C2H5OH + 2CO2

Question 38

What does the breakdown of glucose

Answer 38

Enzymes in the yeast

Question 39

Examples of things that can be used for the glucose in production of ethanol

Answer 39

Sugar cane Sugar beef Grapes

Question 40

Why is the concentration of ethanol around 10-20%

Answer 40

Because the yeast dies

Question 41

What is used to concentrate the ethanol

Answer 41

Fractional distillation Then a Leibig condenser

Question 42

How to measure which alcohol is the most efficient fuel

Answer 42

Spirit burner with alcohol in it and use a mass balance to measure the mass Measure 100cm^3 of distilled water into a copper calorimeter Insulate the container Cover with an insulating lid Take initial temp Light wick Stir When temp has increased by 20 degrees blow out the wick Reweigh immediately Repeat

Question 43

What are the size of nanoparticles

Answer 43

1-100 nanometers across

Question 44

What is a nanoparticle surface area to volume ratio like

Answer 44

High

Question 45

Uses of nanoparticles

Answer 45

Catalysts (high SA to V ratio) Cosmetics - eg. sunscreen Electric circuits (conduct electricity) Sports equipment plastics (durable and stronger)

Question 46

What could potential problems of nanoparticles be

Answer 46

They don't break down as easily so perhaps they could start to build up in cells and cause problems such as lung inflammation

Question 47

What are composites

Answer 47

They are made of one material (the reinforcement) embedded in another (matrix)

Question 48

What happens when ethanol + oxygen

Answer 48

Carboxylic acid formed

Question 49

How are esters formed

Answer 49

Carboxylic acid + water Characteristic smells Insoluble in water