Flashcards
changes of state + latent heat
Cards in this deck (14)
- 1_______ is needed to melt a solid or boil a liquid.ENERGY
- 2For any pure substance undergoing a change of state--its temperature stays the same whilst the change of state takes place.
- 3What changes happen at the: a) melting point b) boiling pointa) melting + freezing
b) boiling + condensation - 4What can affect the melting/boiling points of a liquid? Give an example.any impurities in a substance
e.g. the melting point of water is lowered if you add salt to the water - 5Describe what happens during the horizontal sections of the graph.during this time, the extra heat added does not go to increasing the temperature, but rather to overcome the force of attraction between the particles, hence the reason why the temperature stays the same
- 6What is the difference between evaporation and boiling?evaporation: happens at any temperature and at the surface of the liquid
boiling: at the boiling point, when bubbles of vapour form inside the liquid + rise to the surface to release the gas - 7What can energy added do?1. increase kinetic energy
2. break/ make bonds
(NEVER BOTH at the same time) - 8potential energy == intermolecular forces
- 9What is latent heat?the energy needed for a substance to change its state (and break its bonds) without changing the temperature
- 10Describe specific latent heatthe amount of energy required to melt or boil 1kg of a substance without changing its temperature
- 11Give the formula for specific latent heat.latent heat = energy / mass
- 12What does the amount of energy required to change the state of a sample depend on?1. the substance
2. the state change
3. the mass - 13define specific latent heat of fusionthe energy needed to change the state of 1kg of a substance from solid to liquid
- 14define specific latent heat of vaporisationenergy needed to change the state of 1kg of a substance from liquid to gas
Information
- Description
- • 6.3: changes of state • 6.5: specific latent heat
- Created by
- Farha Idrees
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