Chemistry #6

Question 1

Endothermic

Answer 1

• Involves absorbing energy
• takes in thermal energy from the surroundings leading to a decrease in the temp of the surroundings.

Question 2

Exothermic

Answer 2

• Involves releasing energy
• Transfer thermal energy to the surroundings leading to an increase in the temp of the surroundings.

Question 3

Define enthalpy

Answer 3

Empathy and divine as the change in energy between reacting and products and has the units kj/mol or kj mol -1

Question 4

To improve the yield - haber process

Answer 4

Moderate high pressure (200 atm)
Remove ammonia (decreases concentration if products)

Question 5

To improve the reaction rate

Answer 5

Moderate temperature (450 oC)
Use a catalyst (iron)

Question 6

What is the haber process

Answer 6

Use in the manufacturer of ammonia to produce nitrogen based fertilisers.
Nitrogen is essential mineral for plant growth

Question 7

Contact process

Answer 7

Used to manufacture sulfuric acid H2SO4

Raw materials:
Sulfur, air and water
Or
Sulfur dioxide, and and water

Question 8

Temperature

Answer 8

Increase in temperature favours endothermic

Decrease in temperature favours exothermic

Question 9

Concentration

Answer 9

Increase in reactants favours product side
Increase in products favours reactant side

Question 10

Pressure - gases only

Answer 10

Increase in pressure favours fewer gas moles/molecules

Decrease in pressure favours more gas moles

Question 11

Catalyst

Answer 11

The position of equilibrium does not change

Question 12

Dynamic equilibrium

Answer 12

When the rate of the forward reaction is equal to the rate of the backward reaction.
There is no observable change.
Dynamic means moving
Equilibrium means state of balance