Chemistry Y09 Spr1

Question 1

1.1 State the percentages of nitrogen, oxygen and other gases in the atmosphere.

Answer 1

nitrogen 78%, oxygen 21%, other gases 1%

Question 2

1.2 Name three greenhouse gases.

Answer 2

carbon dioxide, methane, water vapour

Question 3

1.3 Name two ways human activity has increased the amount of methane in the atmosphere.

Answer 3

farming cows and growing rice

Question 4

1.4 Describe how is crude oil formed from.

Answer 4

the remains of ancient biomass (mostly plankton) buried in mud for millions of years.

Question 5

1.5 State the general formula for alkanes.

Answer 5

C_nH_2n+2

Question 6

1.6 Name the first four alkanes.

Answer 6

methane, ethane, propane, butane

Question 7

1.7 State the general formula for alkenes.

Answer 7

C_nH_2n

Question 8

1.8 A process used to separate mixtures of substances with different boiling points

Answer 8

Fractional distillation

Question 9

1.9 The process of breaking down a long hydrocarbon into smaller more useful hydrocarbons

Answer 9

cracking

Question 10

1.1 State the conditions used for cracking.

Answer 10

high temperature and a catalyst

Question 11

1.1 Describe the test and result for an alkene.

Answer 11

add bromine water, orange to colourless

Question 12

1.2 In chemistry terms define a “pure” substance.

Answer 12

a substance made of a single element or compound

Question 13

1.3 Describe the melting and boiling points of pure substances.

Answer 13

one specific temperature

Question 14

1.4 Define formulation.

Answer 14

a complex mixture designed as a useful product

Question 15

1.5 Chromatography….

Answer 15

is a process to separate the components of a mixture of liquids

Question 16

1.6 To calculate Rf values

Answer 16

distance moved by spot divided by distance moved by solvent

Question 17

1.7 Describe the test for hydrogen.

Answer 17

a lit splint, gives a squeaky pop

Question 18

1.8 Describe the test for oxygen.

Answer 18

a glowing splint, will relight

Question 19

1.9 Describe the test for carbon dioxide.

Answer 19

bubble through limewater, turns limewater cloudy

Question 20

1.1 Describe the test for chlorine.

Answer 20

damp blue litmus paper, will bleach to white