Energy Changes

Question 1

Energy level diagram is exothermic reactions will be……… than the products

Answer 1

Higher
Energy
Course of reaction

|
—

Question 2

Energy level diagram with activation energy

Answer 2

—n
|
—–

Question 3

Activation energy with catalyst

Answer 3

Catalyst lowers the activation energy because it provides an alternate reaction pathway

Question 4

White anhydrous, copper sulphate powder plus water

Answer 4

XO thermic

Question 5

Bond breaking is_____
Bondmaking is____

Answer 5

Endo thermic
Exothermic
bENDy
mEXican

Question 6

Fuel cell advantages

Answer 6

No moving parts to maintain.
Small relative to electricity produced.
Water produced is useful as drinking water.
Quiet in use.
Only waste product is water.
High-efficiency, over 80%
Good reliability
Environmentally beneficial.
Light and compact.

Can be used for spacecraft vehicles etc

Question 7

Fuel cell disadvantages

Answer 7

Hydrogen is more difficult to store.
Few filling stations around.
Expensive to manufacture.
Lack of infrastructure support.
Not validated or fully developed.
Expensive to produce.
Not widely used.
Using Nathan, as a source of hydrogen is not ideal, finite fossil fuel

Question 8

Chemical cell advantages

Answer 8

High energy density.
Longer running time.
Portable.
Reduced/low carbon footprint.
Back up sauce.
Renewable energy.
Rechargeable/repeated
Last for long time, if when goes flat, plugged into an external electrical supply
Efficiency around 85%

Can be used for torches mobile phones appliances, etc

Question 9

Chemical cell disadvantages

Answer 9

Non-rechargeable ( alkaline batteries)
Irreversible reaction.
Not very environmental.
Expensive to buy repeatedly?

Question 10

What does a fuel cell do?

Answer 10

Produces voltage continuously if a fuel and oxygen are present

Question 11

What does a chemical cell do?

Answer 11

Use chemical reactions transfer energy
Produce voltage until reactant is used up