Yr9 Chemsitry-Hydrocarbons

Question 1

What is the chemical formula for methane?

Answer 1

CH₄

Question 2

Why are alkanes called hydrocarbons?

Answer 2

They only have hydrogen and carbon

Question 3

If you look at the name how can you tell if something is a alkane?

Answer 3

It needs to end in -ane

Question 4

Which of these are not alkanes?

Methane

Ethanol

Butane

Pentene

Ethane

Ethanoic acid

how did you find this out?

Answer 4

Ethanol

Pentene

Ethanoic acid

Don’t end in -ane

Question 5

What is the formula of an alkane?

Answer 5

C_nH_{2n + 2}

Question 6

How many hydrogens would an alkane with 8 carbons have?

Answer 6

18

Question 7

What is the equation for complete combustion?

Answer 7

CH₄ + 2O₂ –> 2H₂O + CO₂

Question 8

What is the equation for incomplete combustion?

Answer 8

2CH₄ + 3O₂ –> 4H₂O + 2CO

Question 9

What is viscosity?

Answer 9

How runny something is

Question 10

What is flamibility?

Answer 10

How well it burns

Question 11

Why isn’t C₁₅H₃₂ an ideal cooking feul?

Answer 11

C₁₅H₃₂ isn’t an ideal cooking as the long chains of carbon mke it have a smoky flame and doesn’t burn as well as other alkanes.

Question 12

Which of these emmisions are poisinous?

Carbon Dioxide

Water

Nitrogen

Carbon Monoxide

Nitrogen monixide

Particles of Carbon

Answer 12

Carbon monixide

Pacticles of carbon

Carbon Dioxide

Nitrogen monoxide

Question 13

What decomposes to make crude oil?

Answer 13

Marine Life

Question 14

How long does crude oil take to form?

Answer 14

Millions of years

Question 15

How do we extract crude oil?

Answer 15

Pump it up through pipes.

Question 16

Why do we need a alternative to crude oil?

Answer 16

It is running out

Question 17

How do we release energy from crude oil?

Answer 17

Burn it

Question 18

What is used to seperate crude oil?

Answer 18

Fractional Distilation

Question 19

What is the formula for alkenes?

Answer 19

C_nH_2n

Question 20

Which of these are alkenes?

Metane

Ethane

Hexane

Pentene

Hexene

Ethanoic acid

Dodecene

How did you know?

Answer 20

Pentene

Hexene

Dodecene

They all end in -ene

Question 21

What do alkenes react with to produce alkanes?

Answer 21

Hydrogen

Question 22

What do alkenes react with to produce an alchohol?

Answer 22

Steam

Question 23

What is the formula for alchohols?

Answer 23

C_nH_{2n + 1}OH

Question 24

What are the properties of carboxylic acids?

Answer 24

High melting points

Very soluble in water

Weak acids

Characteristic smell

Question 25

What is the formula for carboxylic acids?

Answer 25

C_nH_{2n + 1}COOH

Question 26

How do you make an ester?

Answer 26

Heat a carboxylic acid and an alcohol together with a concentrated sulphuric acid.

Question 27

If I heat methanoic acid with ethanol what ester would I get?

Answer 27

Ehtyl methanoate and water

Question 28

What are polymers?

Answer 28

Long chained molecules made from single units called monomers

Question 29

Match the monomer with the polymer

Styrene Poly(chloroethene)

Ethene Poly(propene)

Chloroethene Poly(styrene)

Propene Poly(ethene) (Polythene)

Answer 29

Styrene Poly(styrene)

Ethene Poly(ethene) (Polythene)

Chloroethene Poly(chloroethene)

Propene Poly(propene)

Question 30

Use the words below to fill in the gaps

tempurature, monomers, different, molecules

Polymers are giant _{……………………}. They are made by joining small molecules called _{……………………..} together. Different polymers such as poly(ethene) and poly(propene) have _{…………………} physical proerties. The physical properties of a polymer such as polyethene are affected by the conditions used when they’re made such as _{…………………} and pressure.

Answer 30

Polymers are giant molecules They are made by joining small molecules called monomers together. Different polymers such as poly(ethene) and poly(propene) have different physical proerties. The physical properties of a polymer such as polyethene are affected by the conditions used when they’re made such as temperature and pressure.

Question 31

Which of these are true?

The monomer of poly(ethene) is ethene

The polymer of poly(ethene) is ethane

The monomer of poly(ethene) is ethane

Answer 31

The monomer of poly(ethene) is ethene