phase changes

• Natuurkunde / Scheikunde
• Middelbare school
• vwo
• Leerjaar 1

which phase does not have a fixed volume?

1. solid
2. liquid
3. gas
4. magma

what do we mean by adhesion?

1. The attraction between molecules of the same substance
2. the attraction between molecules of different substances

How do we call the phase change from gas into solid?

How do we call the phase change from liquid into solid

The melting point of parafine is 69C. Calculate the temperature in K

sea water (salty water) has a lower freezing point than plain water. It is 260K. Calculate the temperature in C.

why does a hot air balloon fly?

1. heated air always rises
2. the density of heated air is smaller
3. the density of heated air is bigger
4. it must be magic

what has the bigger density: liquid water or ice?

1. ice, because it is a solid
2. ice, because it is colder
3. water, because ice floats on water
4. water, because it is a liquid

density decreases with higher temperature

Which liquid has the greater density: water at 0 °C or water at 2 °C? Explain your answer

1. water at 0 °C
2. water at 2 °C

why does a puddle of water evaporates, even at room temperature?

1. it doesn't. The water must boil first
2. water always evaporates, independent of temp
3. water can evaporate at the surface
4. it depends on air pressure

whhh

1. both liquids are pure substances
2. both liquids are mixtures
3. the left liquid is a mixture, the right is a pure substance
4. the left liquid is a pure substance, the right is a mixture