Paper 2- Unit 8 Chemical tests Flashcards
An element is
a substance made of only one type of atom
A compound is
a substance made of two or more different types of atoms
that are chemically bonded
A mixture is
a substance made of 2 or more different elements or compounds
that can be separated (as they are unbonded)
A pure substance is…
something that contains only one type of element or compound
nothing else is mixed in
Examples of natural mixtures
milk
cheese
air
A formulation is…
a useful man-made mixture
Formulations are made by…
mixing two or more compounds together
Examples of useful formulations
fuels, cleaning agents, plants, medicines, alloys
What is an alloy
A mixture when at least one of the elements in a metal
Test for hydrogen
lit splint
burns rapidly to produce a squeeky pop
Test for oxygen
a glowing splint
will relight
Test for chlorine
damp litmus paper
is bleached and turns white
Test for carbon dioxide
Lime water
turns clear to cloudy
when gas i bubbled through it
Describe how to carry out the chromatography practical
1) Draw pencil line 1cm from the bottom of a piece of paper
2) place the pigment drop on the pencil line
3) place the paper in a beaker with water just touching the bottom of the paper
4) wait for the water to travel up the paper
5) measure the distance the pigment has moved through the paper and the distance the paper has moved
What does chromatography tell us?
How many difference colours are in a dye
the number of spots are the number of pigments
