How Much? Flashcards
(27 cards)
What is the relative atomic mass?2
The mass of the atoms of an element compared to Carbon-12
( which is given a mass of exactly 12)
How are isotopes different from normal atoms?
- Because hey have a different number of neutrons the nucleus can be unstable
- And possibly radioactive
- Different density
What is a polymer? 2
A substance made from very large molecules
Made up of repeating units
What factors affect the properties of polymers?2
1 the monomers used to make them
2 the conditions chosen to carry out the reaction
What is a thermosetting polymer?2
Will not soften
but will eventually char if heated very strongly
What is a thermos offending polymer?
Will soften or melt easily when heated
Definition of nano science?
The study of small particles between 1 to 100 nanometers in size
What is an isotope?2
- Atoms of the same element with a different number of NEUTRONS
- but the same number of protons
What does gas chromatography do to a mixture?
Separates the solvents
Two advantages of gas chromatography compared with paper chromatography?2
- accurate
- quicker
Why might a question not be able to be answered by science alone?3
- based on opinions
- ethical issue
- can’t be done by an experiment
How does gas chromatography separate substances in a mixture of compounds?3
- substances carried by gas
- through a tube
- at different speeds
Why do different compounds separate in a gas chromatography column?
Distances substances travel at different speeds
Why use pencil in a chromatography column?
Ink would run and effect the results
What determines the position on the ph scale?
Hydrogen
Why might something not be able to be proven by science?
Based on opinion
Ethical social or economic issue
Cannot be done by experiment
Why might a maximum yield not be obtained?
Reversible reaction
Escape to surroundings
Unexpected reactant
With a solid, how do you get it from a mixture?
Filter
What products do you get from sodium chloride solution?
Hydrogen
Sodium hydroxide
Chlorine
How can you confirm the reliability of an experiment?
Compare to other results
Another scientist doing the same experiment
why might it not be possible to obtain the calculated amount of product?
Reversible so reaction isn’t completed
Some product may be lost in deprecation
Reactants may react in a different way than expected
Gas chromatography and mass spectrometry?
Time taken for a substance to travel through the column can be used to help identify the substance
Output from the gas chromatography column can be linked to a mass spectrometer which can be used to identify substances leaving end of column
What does the number of peaks on the output of a gas chromatograph?
The number of compounds present
What does the position of peaks on the output of a gas chromatograph?
Position of peaks indicates retention time
