A pure substance has to be an element
A mixture is always an impure substance.
Impure substances have higher boiling points
Salt is put on ice to increase the melting point.
Identify 2 differences between pure and impure substances
What happens to the melting point of water when impurities are added?
Explain why salt is placed on roads in winter months?
What is a pure substance made up of only one type of atom?
Simple distillation allows us to separate liquids with different boiling points.
How many substances are in dye A?
How many substances are in Dye B?
Explain how the chromatogram shows that A is a pure substance and B is a mixture.
In chromatography, ink is the solvent.
Why is the start line drawn in pencil rather than pen?
Chromatography allows us to separate different elements in a compound.
In chromatography, the dyes are soluble in water.
What colours are in substance P?
Put the order of Chromatography in order
Draw a line with a pencil and ruler to one end of the strip of filter paper
When the solvent has almost reached the top of the filter paper, remove it from the beaker
Use a ruler to measure the distance the ink spot has travelled (Rf values)
Place a spot of ink on the pencil line
Suspend the filter paper in a beaker so it isn't touching the sides or the bottom
Lay the paper flat and leave it to dry
Cover the beaker and wait a few minutes
Carefully add the solvent to a level just below the ink spot, taking care not to splash the paper
Match the gas test to its positive result
| Stavka koja se može prevući | arrow_right_alt | Odgovarajuća stavka |
|---|---|---|
Put Damp litmus paper into the gas | arrow_right_alt | Limewater turns milky (cloudy) |
Hold a burning splint at the open end of a test tube of the gas | arrow_right_alt | Litmus paper is bleached and turns white |
Place a glowing splint in a test tube of the gas | arrow_right_alt | A squeaky pop sound is produced |
Shakes or bubble the gas through limewater | arrow_right_alt | The splint relights. |
