Solids, Liquids and Gases are the three main states of matter.
Which is the correct order of state changes?
Answer
Solid (evaporation) --> Liquid
Liquid (freezing) --> Gas
Gas (condensation) --> Liquid
Gas (sublimation) --> Solid
Question 2
Question
Which of the following are the ways in which fresh water is sterilised?
Answer
UV radiation
chlorine
ozone
IR radiation
hydrogenation
Question 3
Question
Complete the following sentences about treating fresh water.
In the United Kingdom (UK), rain provides water with low levels of dissolved substances (called [blank_start]fresh[blank_end] water) that collects in the ground and in lakes and rivers.
To make this water potable, it must go through these steps:
[blank_start]sedimentation[blank_end] - solids sink to the bottom and are removed
[blank_start]filtration[blank_end] - fine particles like sand are removed
sterilising - microbes are [blank_start]killed[blank_end]
Answer
sedimentation
filtration
killed
fresh
Question 4
Question
Paper chromatography works because some of the coloured substances are better at dissolving in the liquid than they are at bonding with the paper, so they travel further [blank_start]up[blank_end] the paper.
Answer
up
Question 5
Question
[blank_start]Filtration[blank_end] is a method for separating an [blank_start]insoluble[blank_end] solid from a liquid. A mixture of liquid and solid is passed through filter paper into a flask below. The solid stays on the filter paper ([blank_start]residue[blank_end]), and the liquid passes through to the container below ([blank_start]filtrate[blank_end]).
[blank_start]Crystallisation/evaporation[blank_end] is a method that separates a [blank_start]soluble[blank_end] solid from a liquid. A solution of liquid and dissolved solid is heated, causing the solvent to evaporate and leaves solid crystals behind.
[blank_start]Simple distillation[blank_end] is a method for separating the [blank_start]solvent[blank_end] from a solution, leaving behind the solute. This method works because the solvent has a much lower boiling point than the dissolved solute. Heating the solution allows the solvent to evaporate, and then it passes through a condenser, where it is cooled and condensed into a separate container. The [blank_start]solute[blank_end] does not evaporate and so it stays behind.
[blank_start]Fractional distillation[blank_end] is a method of separating multiple [blank_start]liquids[blank_end] from each other. The technique works in the same way as distillation, but on a much larger scale.
Answer
Filtration
Crystallisation/evaporation
Simple distillation
Fractional distillation
insoluble
soluble
solvent
filtrate
residue
solute
liquids
solids
gases
Question 6
Question
A pure substance is either a single element, or compound, that is not mixed with any other substance.
Answer
True
False
Question 7
Question
Calculate the Rf value of the red spot if it moved 7 cm, and the solvent moved 9 cm (2 d.p.).
[blank_start]0.78[blank_end]
Paper chromatography consists of two stages:
the [blank_start]stationary[blank_end] phase (a.k.a. the phase that doesn't move - this is the [blank_start]paper[blank_end])
the [blank_start]mobile[blank_end] phase (a.k.a. the phase that moves - this is the [blank_start]solvent[blank_end])