The Nitrogen Cycle

Question 1

What is the symbol that denotes nitrogen gas?

Answer 1

N2

Question 2

What type of gas is nitrogen and what percentage of the atmosphere is it?

Answer 2

It is an inert gas and is 78% of the atmosphere.

Question 3

Name a characteristic for nitrogen.

Answer 3

It has a high triple bond.

Question 4

How many isotopes does Nitrogen have and state them.

Answer 4

1) N14

2) N15

Question 5

How many oxidation states does nitrogen have?

Answer 5

8

Question 6

Where is nitrogen found?

Answer 6

It is found in proteins and they are made out of amino acids.

Question 7

Why is Nitrogen in DNA?

Answer 7

Because DNA is made of nucleotides.

Question 8

How do we know nitrogen plays a key role in life?

Answer 8

Because it is a component in the formula for a cell.

Question 9

How can nitrogen be an air pollutant?

Answer 9

Because of Nitrogen oxides caused due to combustion of fossil fuels (that contain nitrogen).

Question 10

What are the consequences of nitrogen oxides?

Answer 10

They can cause lung damage and asthma.

Question 11

What does NO2 (Nitrogen dioxide)?

Answer 11

The greenhouse effect.

Question 12

How can nitrogen be an aquatic pollutant?

Answer 12

Because proteins break down to ammonia, which is known as ammonification, and ammonia is toxic to fish.

Question 13

What does NOEC stand for?

Answer 13

No effect concentration.

Question 14

Across a 4 day average how much mg/l of ammonia is in a river?

Answer 14

0.02mg/l

Question 15

When does the amount of mg/l of ammonia become lethal?

Answer 15

1mg/l

Question 16

How many mg/l of ammonia are in raw sewage?

Answer 16

40mg/l

Question 17

How is nitrogen a risk to babies?

Answer 17

Because of Methane Haemoglobin, caused by nitrate, this nitrate will bind with the haemoglobin and prevent haemoglobin operating correctly and this asphyxiates the babies (blue baby syndrome).

Question 18

How does Nitrate get into the drinking water?

Answer 18

Due to heavy agricultural pollution, where a lot of fertiliser containing nitrogen is on an area of land, then a lot of nitrogen will go into the soil get converted into nitrate and goes down into the water contaminating it.

Question 19

if you want a cell to grow what 5 things do you need?

Answer 19

1) Carbon
2) Hydrogen
3) Oxygen
4) Nitrogen
5) Phosphorus

Question 20

What is Liebig’s law of limiting factors?

Answer 20

Growth id limited by scarcest resources.

Question 21

What is photosynthetic organisms limited by?

Answer 21

Nitrogen and phosphorus.

Question 22

How can fuel for flights be created?

Answer 22

From algae grown in ponds.

Question 23

What limits our ability to grow algae for bio-fuels?

Answer 23

Nitrogen and phosphorus.

Question 24

What is key in the nitrogen cycle?

Answer 24

Energy

Question 25

What are the 4 steps to the nitrogen cycle?

Answer 25

1) Start with Nitrogen gas then nitrogen fixation occurs
2) This results in Organic Nitrogen, then ammonification occurs
3) Resulting in ammonium, then nitrification occurs
4) And you the product of this is Nitrate, then denitrification happens starting the cycle again.

Question 26

What are all Geo-chemicals cycle driven by?

Answer 26

Reduction- Gain in electrons

Oxidation- Losing electrons

Question 27

What two things is the energy doing in the cycle?

Answer 27

Either being released or incorporated.

Question 28

Describe nitrogen fixation.

Answer 28

Bacteria and algae release energy but huge amounts of energy is required to break triple bonds. This can happen unnaturally through the Haber process.

Question 29

What does OILRIG stand for?

Answer 29

Oxidation is lose reduction is gain.

Question 30

Describe the Haber process.

Answer 30

1) Occurs at 200 atmospheres
2) At 400 Degrees Celsius
3) it produce 120 million tonnes of Nitrogen gas each year

Question 31

What happens to ammonia during Nitrogen fixation?

Answer 31

It is converted into amino acids.

Question 32

Describe ammonification.

Answer 32

Proteins and other materials break down into ammonia.

Question 33

What are wastes a mixture of?

Answer 33

Organic nitrogen (such as amino acids) and ammonia this organic nitrogen + ammonia = Total Kjeldahl Nitrogen (TKN).

Question 34

What is nitrification?

Answer 34

It is a two step process involving distinct groups of bacteria ammonia oxidation (Ammonia Oxidising bacteria). Where ammonia is the electron donor and oxygen is the electron acceptor.

Question 35

How do microbes get energy?

Answer 35

By transferring electrons from donors to acceptors.

Question 36

Describe denitrification.

Answer 36

Nitrate is the electron acceptor and Carbon is the electron donor. Denitrification is denitrifying bacteria and this leads to the production of nitrogen gas.

Question 37

What are the engineering interventions in the Nitrogen cycle? (2)

Answer 37

1) Protecting groundwater by monitoring the nitrate levels.

2) Protecting Lakes by monitoring the Nitrogen and Phosphorus levels.

Question 38

Describe some features of the Esholt Treatment works. (3)

Answer 38

1) Effluent standard changed from 4mg/l to 2mg/l
2) Huge new plant
3) 1 million per year in electricity was used to power the plant.