C2.1 Flashcards
What is the relative atomic mass (R.A.M or Ar)
The mean mass of an atom of an element compared to 1/12 the mass of a carbon 12 atom
What is the relative formula mass (R.F.M or Mr)
The mean mass of a unit of a substance compared to 1/12 the mass of a carbon 12 atom
What is the empirical formula
An empirical formula shows the simplest whole number ratio of the atoms of each element in a compound
What is a pure substance in science
A substance that contains just one element or compound
What is a solute
A solid that you are trying to dissolve
Solvent
The liquid used to dissolve the solid
Solution
The dissolved solute and solvent together
What does soluble mean
A dissolvable solid
What does insoluble mean
A solid that doesn’t dissolve
What is simple distillation
It separates a solvent from a solution. It relies on the solvent having a much lower boiling point than the solute. When the solution is heated, the solvent boils but the solute does not. The solvent escapes from the solution in its gas state by a condenser. It is then cooled and condensed back to its liquid state by a condenser.
What is fractional distillation
Fractional distillation separates two or more substances from a mixture in the liquid state. It relies on each substance having a different boiling point and uses a special piece of equipment called a fractionating column.
What does a labelled diagram of simple distillation of impure water contain
Thermometer Hot water vapour Impure water boiling Heat Vapour condenses to liquid in the condenser Test tube Cooling water out Purified water Cooling water in
What apparatus does fractional distillation contain
Everything in simple distillation but it has a fractionating column as well.
What is the mobile phase in paper chromatography
The substance that moves
What is the stationary phase in paper chromatography
The paper
What does the bonding of the stationary and mobile phase do
It affects how high or low the ink/subject moves
What is usually in thin layer chromatography
Usually in a tank Not water but a solvent Has a lid Has a TLC plate Has a line and an x sample
What is the stationary phase in Thin-layer chromatography
A plate of glass or plastic but it has a thin layer of alumina or silica powder spread over it
How do you calculate the retention factor (Rf) in chromatography
Distance travelled by substance
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Distance travelled by solvent
What do Rf values vary from
They vary from 0 - 1 and have no units. They are also in 2 decimal places
What is the mobile phase in gas chromatography
An unreactive carrier gas such as nitrogen which does not react with the sample
How would you separate salt in seawater (6 marks)
- Bunsen burner would heat up the seawater at a blue flame
- The water would evaporate up from the round bottom flask when it reaches 100 degrees Celsius.
- The evaporated water would go up the evaporating tube and into the condenser
- The evaporated gas would then go through the condenser where cooling water is flowing through around it and the gas will condense.
- The pure water will drip down onto the beaker and the salt will be left over
- The distillate is in the beaker and the salt is in the round bottomed flask and you would turn off the Bunsen burner.
