Topic 5

Question 1

What group are halogens in

Answer 1

Group 7

Question 2

Halogens have…….properties

Answer 2

Similar

Question 3

Name properties of chlorine(halogen)

Answer 3

Fairly reactive
Poisonous
Dense green gas

Question 4

Name properties of bromine

Answer 4

Dense
Poisonous
Orange liquid

Question 5

Name properties of iodine

Answer 5

Dark gray

Crystallised solid

Question 6

What do halogens when react with metals form

Answer 6

Metal halides

E.g metals iron, aluminium

Question 7

What do halogens form when reacted with hydrogen

Answer 7

Hydrogen halides

Question 8

Are halogens soluble or insoluble and what do they form in water

Answer 8

Soluble

Form Acidic solutions

Question 9

The higher up group 7 the…(halogens)

Answer 9

More reactive as outer shell nearer to nucleus

Pull apart from positive nucleus is greater which attracts extra electrons more strongly

Question 10

How do more reactive halogens displace less reactive ones in reactions

Answer 10

When halides dissolve in water halide ions are free to react

More reactive halogen reacts with a solution containing halide ions it will “push out”(displace) less reactive halogen

Question 11

How are Nobel gases seen at room temperature

Answer 11

Are all colourless gases

Question 12

Why are very few Nobel gases reactive

Answer 12

Because have full outer shells

Question 13

What happens to the boiling points as you go down the group

Answer 13

They increase

Question 14

How where Nobel gases discovered

Answer 14

When chemists noticed that the density of nitrogen made in chemical reactions was different to that of nitrogen taken from the air

Question 15

What is argon used for and why (Noble gas)

Answer 15

Is inert and non flammable so used in filament lamps to stop filament burning away
Protects metals being welded as inert atmosphere stops the hot metal reacting with oxygen

Question 16

What is helium used for and why (noble gas)

Answer 16

In airships and party balloons because lower density than air so will float

Question 17

What happens in chemical reactions

Answer 17

Energy is usually transfused to and from the surroundings making and breaking bonds

Question 18

What is always needed to break bonds

Answer 18

Energy

Question 19

What happens in and exoteric reaction

Answer 19

Overall gives out energy to the surroundings intdhe form of heat shown in a rise in temperature

Question 20

Give an example of two reactions that give out heat (exothermic)

Answer 20

Burning fuels

Explosions

Question 21

What is an endothermic reaction

Answer 21

One which overall takes in energy shown in a fall in temperature

Question 22

Give two examples of endothermic reactions

Answer 22

Photosynthesis

Ammonium nitrate

Question 23

What is more common endothermic or exothermic

Answer 23

Exothermic

Question 24

What would an exothermic graph look like and why

Answer 24

Initial rise due to energy needed to break old bonds the decrease in temp as heat is given out in the reaction putting the product at a lower temp

Question 25

What would an endothermic reaction look like on a graph and why

Answer 25

Product at a higher energy than reactant showing the energy taken in during the reaction

Question 26

What are the four ways of measuring temperature change in a reaction

Answer 26

Dissolved salts Neutralisation Displacement Precipitation reactions

Question 27

How would you reduce heat loss to surroundings in a reaction

Answer 27

Put polystyrene cup in beaker with wool to give insulation | Put lid on to reduce energy loss by evaporation

Question 28

Name the three different rates of reactions and examples of them

Answer 28

Slowest- rusting of iron Moderate- a metal reacting with an acid Fast- explosion

Question 29

What do the rates of reaction depend on

Answer 29

Temperature Concentration or pressure(for gases) Catalysts Surface area

Question 30

What does the reaction of hydrochloric acid and marble chips produce and what is the catalyst

Answer 30

CO2 | Marble chips

Question 31

Name two independent variable that would change the rate of reaction of marble chips and hydrochloric acid

Answer 31

Surface area do marble chips | Concentration of HCL

Question 32

What will a higher temp change of an experiment and give an example

Answer 32

Will produce quicker reaction Will produce cloudy precipitate that will cause a black mark in test tube to disappear which you can time how long it takes to disappear E.g Sodium thiosulfate and HCL or marble chip and HCL

Question 33

What is a catalyst

Answer 33

Something that speeds up the rate of reaction but is not used up in the reaction

Question 34

What is the advantages of using a catalysts

Answer 34

Lower energy required Increase rate of reaction Increase temp without rate of reaction dropping

Question 35

A use of catalysts

Answer 35

Catalytic converters in cars- vehicle exhausts can give of toxic gas Carbon monoxide Increases the amount of time it takes for carbon monoxide to react with O2 in air to produce CO2 and H2O

Question 36

What is collision theory

Answer 36

Rate of reactions depend on how often and how hard reacting particles collide with each other

Question 37

Faster collisions are only caused by

Answer 37

Increase in temperature

Question 38

Name three collision to change the rate of reaction

Answer 38

Concentration (pressure for gases) Temperature Surface area Catalyst