C1 - Air and Water

Question 1

What where the main ideas in daltons atomic model

Answer 1

Atoms are tiny solid balls which can’t be broken down
All atoms of an element are identical
Atoms of different elements are different
Atoms from different elements combine to make compounds
Atoms are rearranged during a chemical reaction to make new substances

Question 2

What did Thomson discover

Answer 2

He discovered electrons

Question 3

Who discovered electrons

Answer 3

Thomson

Question 4

What is an isotope

Answer 4

An atom with the same number of protons and electrons but with a different number of neutrons

Question 5

What is formed in the reaction between group 1 elements and water

Answer 5

Metal hydroxide and hydrogen

Question 6

What is the appearance of chlorine

Answer 6

yellow green gas

Question 7

What is the appearance of bromine

Answer 7

deep red liquid

Question 8

What is the appearance of iodine

Answer 8

grey solid

Question 9

What is the colour of iodine as a gas

Answer 9

Purple

Question 10

Formula for ammonia

Answer 10

NH3

Question 11

Formula for chlorine

Answer 11

Cl2

Question 12

Does breaking a bond release or require energy

Answer 12

breaking bonds requires energy

Question 13

overall energy change (in a chemical reaction) =

Answer 13

energy required to break bonds / energy released by forming bonds

Question 14

if the overall energy change is negative was it endo or exo

Answer 14

exothermic

Question 15

What was phase 1 of our atmosphere?

Answer 15

volcanoes gave out gases

Question 16

What gases did volcanoes release into our atmosphere

Answer 16

N2, H2O, NH3

Question 17

What is phase 2 of our atmosphere

Answer 17

As the earth cooled, the water vapour formed our oceans
Algae and plants began absorbing CO2

Question 18

What is phase 3 of our atmosphere

Answer 18

Plants and algae, produced oxygen into our atmosphere

Question 19

Why does coal cause acid rain

Answer 19

Because coal contains sulphur impurities, and when coal is burnt, sulphur dioxide is released

Question 20

How does sulphur dioxide cause acid rain

Answer 20

When it mixes with clouds it forms dilute sulphuric acid, which is acidic

Question 21

How are nitrogen oxides made

Answer 21

the heat from combustion causes oxygen in the air and nitrogen in the air to react together

Question 22

What are some effects of acid rain

Answer 22

kills plants, damages buildings, and corrodes metals

Question 23

What do catalytic converters do

Answer 23

remove nitrogen oxides from exhaust gases

Question 24

What doe acid gas scrubbers do

Answer 24

reduce harmful gases from power station emissions

Question 25

Test for chlorine gas

Answer 25

Chlorine bleaches damp blue litmus paper, turning it white

Question 26

What is the activation energy in an endothermic reaction

Answer 26

the distance from the reactants line to the top of the curve

Question 27

are most neutralization reactions exo or endothermic

Answer 27

exothermic

Question 28

does breaking a bond require or release energy

Answer 28

breaking a bond requires energy

Question 29

does making a bond require or release energy

Answer 29

making a bond releases energy

Question 30

if the overall energy change is negative, is it an endo or exothermic reaction

Answer 30

exo

Question 31

What was the first phase of our atmoshpere

Answer 31

Volcanoes gave out gases

Question 32

What gases did volcanoes release

Answer 32

ammonia, methane, water and co2

Question 33

What was the second phases of our atmosphere

Answer 33

the oceans and plants in the oceans absorbed the carbon dioxide in our atmospehre

Question 34

What was the third phase of our atmosphere

Answer 34

the plants and algae produce oxygen

Question 35

What is released during incomplete compustion

Answer 35

CO, H2O, and carbon particulates in the form of soot

Question 36

What other gas is made during combustion of coal, and why does this happen

Answer 36

sulphur dioxide is made, and this happens because` of sulphur impurities found in coal

Question 37

How do power stations reduce the emissions of harmful gasses

Answer 37

acid gas scrubbers

Question 38

How do cars reduce the emissions of harmful gasses

Answer 38

catalytic converters

Question 39

ammonia

Answer 39

NH3

Question 40

Test for hydrogen

Answer 40

Squeaky pop

Question 41

Test for oxygen

Answer 41

glowing splint will reignite

Question 42

Test for CO2

Answer 42

gas will turn limewater a milky white

Question 43

Test for chlorine

Answer 43

Chlorine will bleach a blue piece of DAMP litmus paper white

Question 44

In a hydrogen fuel cell, which electrode is positive

Answer 44

the cathode

Question 45

what enters the fuel cell on the negative, anode side

Answer 45

H2

Question 46

what enters the fuel cell on the positive, cathode side

Answer 46

O2

Question 47

What happens to the H2 at the anode (negative)

Answer 47

It oxidises the hydrogen, and the electrons flow through the wire running from the anode to the cathode. The H+ ions then travel through the electrolyte, to the cathode (positive)

Question 48

What happens at the cathode in a fuel cell

Answer 48

the electrons and the H+ion combines with the O2 to form water

Question 49

What pH is considered a safe drinking water

Answer 49

6.5 - 8.5

Question 50

What are the 4 steps of water treatment

Answer 50

pass through wire mesh to catch large solids pass through sand and gravel to catch smaller solids pump air through water to encourage the growth of aerobic bacteria (breaks down organic matter) chlorine is pumped through, which kills micro organisms

Question 51

What is reverse osmosis

Answer 51

Salty water is passed through a membrane which only allows water to pass through