states of matter ( checklist) Flashcards
spec
when a solid is heated, what happens ( particles and state)
- particles gain more kinetic energy
- this makes the particles vibrate more, weakening the forces holding the solid together
- at a certain temp. the particles break free from their bonds (melting)
this temperature is called the melting point
it has then melted so become a liquid
when a liquid is heated, what happens (particles and state)
- particles get even more kinetic energy
- this energy makes the particles move faster, weakening the bonds holding it together
- At the boiling temperature, particles separate from the bonds and the liquid turns into a gas
when a substance changes state, does its temperature change ?
no
why does a substance not change temperature when changing state ? (heating)
because the energy you are putting in is being used to overcome the forces of attraction between the particles rather than speed up the movement
why does a substance not change temperature when changing state ? (cooling)
when you cool a substance, then energy being released is coming from the formation of new forces and is not being released from the slowing down of particles so temp stays the same.
in a cooling curve, will the line travel from top to bottom or bottom to top
top to bottom
in heating and cooling curves, what do the flat bits mean
they’re when the substance is changing state
what do the 45º lines man in heating & cooling curves
temperature of substance are changing
increasing the pressure of a gas will ____ its volume
why
the particles in a gas are far apart, if you increase the pressure you are pushing them closer together so volume decreases
decrease
increasing the temperature of a gas will ____ its volume
why
increase
if you heat a gas, the particles move faster and gain more kinetic energy. because they are faster and have more energy they will travel further, increasing the volume.
gas to liquid
condensing
liquid to gas
evaporating
liquid to solid
freezing
solid to liquid
melting
gas to solid
sublimation
what is diffusion
when a substance changes from an area of high concentration to an area of low concentration
dilution experiments support a theory that ?
all matter, solids, liquids and gases is made up of tiny moving particles
diffusion of gases experiment /explanation
in the beginning, all the bromine molecules are trapped in the bottom half of container (thin piece of plastic holding it)
since there are a lot of bromine molecules close together, the colour is darker
the upper half contains no bromine but contains atmospheric gases
when you remove the piece of plastic, bromine molecules will move up through the container ( through diffusion)
the particles move randomly, but over time will spread out evenly across container
now the bromine particles are much further apart, and so the colour is much paler
what is a solvent
the liquid in which a solute is dissolved
what is a solute
solid that is dissolved in the solvent
what is a solution
mixture of solute and solvent
what is a saturated solution
A solution that is so full of solute that no more solute can dissolve in it
dilution of solids experiment /explanation
potassium manganate crystals (solute) get dissolved in water (solvent) which forms a dark purple solution
- the potassium manganate molecules move randomly in the solution and are evenly spread
the more water you add, the lighter the colour becomes
- it becomes more dilute as there is less solute, and more solvent in the solution
If 10 g is the maximum amount of solute that dissolves in 100 ml solvent before it becomes saturated, then its solubility is
in 100 ml solvent before it becomes saturated, then its solubility is 10
if you only have 50ml of solvent ( in solubility in g/100g solvent) an 10g is the maximum amount of solute, what is the solubility
20g/ 100ml
double if you only have 50ml, you need 100ml
a solubility curve is a graph that represents
the solubility of a solute at different temperatures
units for solubility
g/100ml
PRACTICAL INVESTIGATE SOLUBILITY OF A SOLID IN WATER AT A SPECIFIC TEMPERATURE
- Set water bath to a specific temperature (choose something reasonable)
- Measure out specific volume of water (100ml for ease)
- Place beaker containing water in the water bath. Monitor temperature until it has reached the temperature of the water bath
- Add a known mass of solid and stir until is has dissolved
- Repeat until no more dissolves
- Note down how much solid dissolved*
