C3.4 Gases, equilibria and ammonia Flashcards Preview

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Flashcards in C3.4 Gases, equilibria and ammonia Deck (26)
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1

How many particles does one mole of any substance contain?

6.02 x 10^23 particles

2

How can you work out the number of moles of any substance?

Number of moles = mass in grams / relative atomic or formula mass

3

What is normal atmospheric pressure equal to?

1 atmosphere

4

What is stated in Avogadro's law?

1 mole of any gas at room temperature and normal atmospheric pressure has a volume of 24dm^3

5

What is the room temperature used in Avogadro's law equal to?

25 C

6

What do fertilisers contain that plants need to make proteins?

Soluble nitrogen compounds

7

Why are fertilisers added to soil?

To promote growth in plants

8

What does the Haber process produce?

Ammonia

9

What is the reaction for the production of ammonia?

Nitrogen + hydrogen ammonia

10

Where is nitrogen obtained from when obtaining ammonia for nitrogenous fertilisers?

The air

11

Where is hydrogen obtained from when obtaining ammonia for nitrogenous fertilisers?

Natural gas

12

What does it mean when a reaction is reversible?

It happens in both the forwards and backwards reactions

13

What gas is natural gas mainly composed of?

Methane

14

What is an advantage of artificial fertilisers?

More crops can be grown so more people can be fed

15

What is the disadvantage of artificial fertilisers?

They can easily be washed out of soil and into rivers and lakes, which can cause eutrophication

16

Why are artificial fertilisers easily washed out of soil?

They're highly soluble

17

What is eutrophication?

The build up of nitrates and phosphates in water which encourages excessive plant and algae growth, leading to a depletion of light and oxygen supplies, which leads to other organisms in the water dying off

18

What happens during an exothermic reaction?

Heat is released because more energy is needed to make bonds than to break them

19

Is bond-making an exothermic or endothermic process?

Exothermic

20

Is bond-breaking an exothermic or endothermic process?

Endothermic

21

What happens during an endothermic reaction?

Heat is taken in because more energy is needed to break bonds than to make them

22

What is dynamic equilibrium?

When the forwards and backwards reactions happen at the same rate

23

What happens if a reaction in equilibrium is subject to a change in conditions?

It will adjust to cancel out the change

24

What conditions are used during the Haber process?

-temperature of 450 degrees
-pressure of 200 atmospheres
-presence of an iron catalyst

25

What happens when equilibrium shifts to the right?

More product is produced

26

Why is a high temperature used during the Haber process even though it shifts equilibrium to the left?

Because if it didn't the reaction would be very slow