Studied by 1 person
What is a pure substance?
A substance that contains a single element or compound
What is an impure substance?
a substance that contains more than one type of element of compound in a mixture
What is chromatography?
A method used to separate different components in a mixture
What is the R1 value in chromatography?
A ratio of how far up the paper a certain spot moves compared to how far the solvent has moved
How do you calculate the R1 value in chromatography?
Distance moved by substance/distance moved by solvent
In chromatography, what does the distance the substance moves up the paper tell you about it?
If it travels far it is very soluble and vice versa
What is a formulation?
A mixture that is designed for a specific purpose
Give two examples of formulations?
Fuels and paints
What is the test for hydrogen?
Lit splint gives a squeaky pop if hydrogen is present
What is the test for oxygen?
Relights a glowing splint if oxygen is present
What is the test for carbon dioxide?
Turns limewater cloudy when bubbled through it
What is the test for chlorine?
Bleaches damp litmus paper
What is a cation?
A positively charged ion
What is a anion?
A negatively charged ion
What compound is used to test for positive ions?
Sodium Hydroxide
What result comes from mixing aluminium ions with sodium hydroxide?
On slow addition of excess sodium hydroxide solution, white precipitate forms that eventually dissolves again with excess sodium hydroxide
What result comes from mixing calcium ions with sodium hydroxide?
On addition of excess sodium hydroxide solution, white precipitate forms that does not dissolve
What result comes from mixing magnesium ions with sodium hydroxide?
On addition of excess sodium hydroxide solution, white precipitate forms that does not dissolve
What result comes from mixing Copper (2) ions with sodium hydroxide?
Forms a blue precipitate
What result comes from mixing Iron (2) ions with sodium hydroxide
Forms a green precipitate
What result comes from mixing Iron (3) ions with sodium hydroxide
Forms a brown precipitate
What is the test and result for finding out if carbonate is an anion?
Add dilute acid. A positive result will cause carbon dioxide to be formed which can be tested for with limewater
What is the test and result for finding out if chloride is an anion?
Add silver nitrate solution in the presence of nitric acid. A positive result will cause white precipitate to be formed
What is the test and result for finding out if bromide is an anion?
Add silver nitrate solution in the presence of nitric acid. A positive result will cause cream precipitate to be formed
What is the test and result for finding out if iodide is an anion?
Add silver nitrate solution in the presence of nitric acid. A positive result will cause yellow precipitate to be formed
What is the test and result for finding out if sulfate is an anion?
Add barium chloride solution in the presence of nitric acid. A positive result will cause white precipitate to be formed
Using the flame test, what flame colour will occur with lithium?
Crimson
Using the flame test, what flame colour will occur with sodium?
Yellow
Using the flame test, what flame colour will occur with potassium?
Lilac
Using the flame test, what flame colour will occur with calcium?
Orange/Red
Using the flame test, what flame colour will occur with copper?
Green
What does instrumental analysis involve?
Using complex scientific equipment to test substances
Give an example of an instrumental analysis method?
Flame Emission Spectroscopy
What is the method for Flame Emission Spectroscopy?
The sample solution is put into a flame and the light given off is passed through a spectroscope. Instead of a human observing a colour, the instrument tells you exactly which wavelength of light is being given off as a line spectrum.
What is a more accurate method instead of "The Flame Test"
Flame Emission Spectroscopy
Name the three substances that dissolve in water?
Ionic Compounds, strong acids, strong alkalines
What is Nitric acid's molecular formula?
HNO3
When testing to see which substances are calcium and magensium, how do you didtinguish the two (as they both from a white precipitate that does not dissolve)?
The Flame Test
Note 
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