Chem paper 2 errors

Question 1

Why are large hydrocarbons cracked to produce smaller ones

Answer 1

• Greater demand for smaller hydrocarbons
• better fuels
• more useful
• used to make alkenes
• used to make polymers

Question 2

The rate of reaction with methonic acid is faster is greater than the rate of reaction with ethonic acid explain why

Answer 2

• Methonic acid has a higher PH
• so the same concentration of methonic acid to ethonic acid has more H+ ion concentration
• This means more particles so increased rate of reaction (more collisons per second)

Question 3

What is a formulation

Answer 3

A mixture that has been designed as a useful product, made by mixing specific substances in carefully measured amounts to give the product the desired properties.

Question 4

advanteges of fermentatoin

Answer 4

Uses renewable resources

Sugar (from sugar cane or beet) is renewable, unlike crude oil.

Low temperature and pressure

Conditions are mild (around 30°C), so it uses less energy than processes like hydration of ethene.

Simple equipment

Doesn’t require expensive high-tech machinery or catalysts.

Can be done in developing countries

Because it’s cheap and doesn’t need complex setups, it’s useful in places with limited resources.

Carbon neutral (partly)

The CO₂ released during fermentation is roughly balanced by the CO₂ absorbed by plants growing for sugar.

Question 5

disadvantage of fermination

Answer 5

Slow process

Fermentation takes longer than industrial methods like hydration of ethene.

Low purity of ethanol

Ethanol made by fermentation is usually around 15% and needs to be purified by distillation, which takes extra energy.

Question 6

Additon reacton to produce alchols disadvantages

Answer 6

Non-renewable

Ethene comes from crude oil, which is a finite (non-renewable) resource.

High energy requirements

Requires high temperature (300°C) and high pressure (60–70 atm) – this uses lots of energy.

Expensive equipment

Needs specialised equipment to handle the high pressure.

Not carbon neutral

Burning fossil fuels releases CO₂, contributing to climate change.

Question 7

advantage of additoin reacton to produce ethonal

Answer 7

Fast reaction

Much faster than fermentation.

Continuous process

Can run non-stop in a factory (unlike batch fermentation), making it more efficient.

High purity ethanol

Produces pure ethanol (nearly 100%) — no need for distillation.

Reliable supply

Ethene can be easily obtained from cracking hydrocarbons in crude oil.

Easily controlled

Conditions (temperature, pressure, catalyst) can be precisely managed in industry.

Question 8

Carboxlic acids react with —– to produce ester

Answer 8

acid

Question 9

Why do scientist think that the theory that an increase in greenhouse gasses causes the increase in global warming

Answer 9

• There may be other reasons in the mean temperature change

Question 10

What is meant by bioleching

Answer 10

• The use of bacteria to produce leachate solutions that contain metals

Question 11

How does different types of chromotography paper effect the Rf values of dyes

Answer 11

• The Rf value changes (gets bigger or smaller)

Because the dyes are more or less attracted to the paper

If a dye is strongly attracted to the paper, it moves less → lower Rf

If it is less attracted, it moves further with the solvent → higher Rf

So, the dye spends more time on the paper or more time moving with the solvent

More time on the paper = moves less = lower Rf

More time with solvent = moves more = higher Rf

Question 12

How does a catalyst increase rates of reaction

Answer 12

• A catalyst provides alternate pathways for the reaction
• Which lowers the activation energy

Question 13

Name the general name for the four general structures which make up DNA

Answer 13

Nuculotides

Question 14

Effect of increasing pressure of a reversable reaction where the number of moles is the same

Answer 14

• No change (on equalibirum)
• Because equal number of gas molucles

Question 15

The effect of adding a catalyst on position of equalibrium

Answer 15

No effect

Question 15

How is potassium chloride obtained from the earth

Answer 15

Mining

Question 16

Explain why phosphate rock cannot be used directly as a fertiliser

Answer 16

Insoubale in water

Question 17

Why is it difficult to identify multiple metal ions in one mixture in a flame

Answer 17

colours mask each other

Question 18

Temperature and pressure for harber proccess

Answer 18

Temp - 450 C
Pressure 200 atm

Question 19

How old is earth

Answer 19

4.6 billion years

Question 20

Rf value

Answer 20

distance traveled by chemical / distance travled by solvent

Question 21

Defination of a ore

Answer 21

An ore is a rock that contains enough of a metal compound to make it economically worthwhile to extract the metal

Question 22

What flame colour is produced by copper sulfate solution

Answer 22

Green

Question 23

Copper sodium hydroxide test

Answer 23

Blue preciptate

Question 24

How is potable water produced from freshwater

Answer 24

- Extract freshwater from rivers, lakes, boreholes - Water passes through filterbeds which removes undisolved solids - Then sterilize using Chlorine which destroys harmfal microbes

Question 25

Steps of water treatment in the uk

Answer 25

- screening and grit removal to remove large particles - sedimentation allows tiny particles to settle out from still water, which produces sewage sludge and effluent (the liquid which remains on top) - the sewage sludge is digested anaerobically by specific bacteria - the effluent is treated with aerobic bacteria to reduce the volume of solid waste

Question 26

How is Liquid Effulent proccesed

Answer 26

Aerobic biological treatment

Question 27

How is solid sewage sludge porccesed

Answer 27

Anerobic digestion

Question 28

Why are some compounds unviewable in cromotrography

Answer 28

Some of the compounds are coloulress

Question 29

Explain why oxides of nitrogen are formed in car engines

Answer 29

- Car engines work at high temps - So in the air nitrogen from air reacts with oxegen forming substences

Question 30

Why may solar energy not be able to replace fossil fuels for energy production

Answer 30

- Sunshine is unrealiable - Lack of space - Increased demand for energy

Question 31

HDPE has a higher density than LDPE, explain why

Answer 31

HDPE monomer chains closer together so more atoms per unit volume

Question 32

Advantages of Industrial procces way of producing large amounts of amonia

Answer 32

- Larger scale - Is Quicker - Continuous judgement

Question 33

Explain proccess of photomining

Answer 33

- Grow plants on area containing ores - Burn plants - Ash dissolved in acid to produce solution of a copper compound - Electrolysis of solution

Question 34

Photomining

Answer 34

Grow plants on copper-rich (low-grade ore) soil so they absorb copper ions. Harvest the plants after they have absorbed the copper. Burn the plants to produce ash that contains copper compounds. Extract copper from the ash using acid and then displace it with scrap iron.

Question 35

Bioleching

Answer 35

Bacteria are used to break down low-grade copper ores. The bacteria produce a solution called a leachate that contains dissolved copper ions. The copper is extracted from the leachate using displacement with scrap iron or electrolysis. It’s a slow but environmentally friendly method that avoids traditional mining.