The Particle Model Level 3 Flashcards
Why is water used as a coolant in factories and power stations?
It has a very high specific heat capacity - so can absorb a lot of energy without a large increase in temperature
Which is larger…specific latent heat of fusion or vaporisation?
Specific latent heat of vaporisation is much larger as the bonds must be broken, not just weakened.
The flat line at the boiling point is much longer than the one at melting point.
Why are burns from steam exceptionally severe?
Because the specific latent heat of vaporisation for water is so large, a lot of energy is given off to the skin when steam condenses to water.
What happens to the temperature of a liquid when it evaporates and why?
The particles with most kinetic energy leave the surface so the average kinetic energy of the remaining particles decreases.
Average ke is the same as temperature, so temperature goes down.
Why can the gradients of the liquid and solid sections of a heating/cooling curve differ?
Because the specific heat capacity of the liquid and solid state of a substance can be different.
Why does a cooling object cool at an increasingly slow rate?
Because the rate of cooling depends on the difference in temperature between the object and it’s surroundings.
