Paper 2 - Topic 8, Chemical Analysis Flashcards
What is chromatography
A technique used to separate mixtures due to the distribution of the substances between the stationary and mobile phase
What’s a Chromatogram
A graph that shows the result of separating the components of a mixture by chromatography
What is the Flame emission spectroscopy
An instrumental method used to analyse metal ions in solutions
What is the flame test
Qualitative test used to identify metal ions (cations), carried out by inserting a nichrome wire loop with the unknown compound on into a flame and observing the colour
What is a formulation
A mixture that has been designed as a useful product, they are made by mixing the components in carefully measure quantities to ensure that the product has the required properties
What is an impure substance
A substance made up of two or more elements or compounds that are not bonded together chemically
What are instrumental methods
Instrumental methods can be used to detect and identify elements and compounds, they are accurate, sensitive and rapid
What is litmus paper
Paper stained with litmus which can identify the acidity or alkalinity of a substance, used to test fro chlorine
What is the mobile phase
Where the molecules can move during chromatography, it is always a liquid or gas
What is precipitation
The creation of a solid from a solution
What is a pure substance
A single element or compound, not mixed with any other substance.
What is the Rf value
The ratio of the distance moved by a compound to the distance moved by the solvent
What is the stationary phase
Where the molecules are stationary during chromatography, it is a solid of a liquid supported on a solid
What are some examples of formulations
- fuels
- cleaning agents
- paints
- medicines
What is the test for hydrogen
Use a burning splint held at the open end of a test tube of the gas, should make a ‘squeaky pop’ sound
What is the test for oxygen
Uses a glowing splint inserted into a test tube of the gas, splint relights in oxygen
How do you test for carbon dioxide
Bubble the gas through the limewater and it will turn cloudy
How do you test for chlorine
Use damp litmus paper, when damp litmus paper is put in chlorine gas, the litmus paper is bleached and turns white
What happens to the colour of a flame if Lithium is present
Turns crimson
What happens to the colour of a flame if sodium is present
It turns yellow
What happens to the colour of a flame if potassium is present
Turns lilac
What happens to the colour of a flame if calcium is present
Turns orange/red
What happens to the colour of a flame if copper is present
Turns green
What happens when a carbonate reacts with a dilute acid
Creates carbon dioxide
