Chemistry C2 Flashcards
What is the value of K?
K=-273.15
What is the function of paper chromatography?
Paper chromatography can be used to separate and subsequently identify small quantities of unknown substances within a solution.
How do you calculate an Rf value?
Divide distance moved by the solute by the overall distance moved by the solvent
What happens when an impure substance is put on paper chromatography?
Impure substances will leave more than the expected number of spots on a chromatogram.
How do you calculate relative molecular mass?
The combined relative atomic mass of all the atoms in a compound or molecule.
What is the name of the unit given to the mass of an atom?
Atomic Mass Unit
what is the dependent variable?
The thing that is measured
What is the independent variable?
The thing that is changed during the course of the investigation. The cause.
What is the control variable?
The thing that doesn’t change.
Name all the SI units and their measurements
Length: metre; mass: kilogram; time: second; amount of substance: mole; temperature : kelvin.
How is the Burette used?
The burette allows volumes of liquid to be added to another and the addition of the liquid is controlled by a tap.
What is the difference between precise results and accurate results?
Precise results are a set of results that are close to one another whilst accurate results are results that are close to the actual value.
What is filtration used for?
separate an insoluble solid from a liquid.
What is evaporation used for?
separate a soluble solid from a liquid.
what is simple distillation used for?
Separate a liquid with a soluble solid or a liquid with another liquid.
