Other Flashcards
(38 cards)
Relative atomic mass symbol
Ar
Relative formula mass symbol
Mr
Ar explanation
The average mass of an atom of an element compared to 1/12th of a C-12 atom
Why is chromatography used
To separate mixtures of substances that are soluble in the same solvent
What’s good about GCMS
Rapid
Accurate
Tiny amounts-sensitive
How GCMS works
Diff substances are carried by a gas through a column packed with solid material.
Travel at diff speeds - separate
Enter detector at diff times
Where is molecular ion peak
Furthest to the right.
Group 1 metal + water
G1M hydroxide + hydrogen
3 points of transition metals
Can have diff charges
Salts are diff colours
Useful catalysts
3 methods of removing water hardness
Boiling temp hard
Adding sodium carbonate
Ion exchange resin
What happens when temp hard water is boiled?
Temp contains HCO3 which decomposes
2HCO3 > CO32- + CO2 + H2O
CO32- ions react with calcium and magnesium to make CaCO3 and MgCO3 limescale
Adding sodium carbonate?
Na2CO3 react with Ca and Mg to make precipitates CaCO3 and MgCO3
Water purification summary
Water passes through screens-remove debris
•sedimentation in settlement tank -sand and oil out
•flocculation as aluminium sulfate makes particles of dirt clump together and settle
•filtration
•chlorine to killlbacteria
•fluorides tooth decay reduction
Energy used per gram
Energy change / mass of fuel
Energy change per mol
Energy change / mol of reactant
Bond energy change (when is it endo/exo)
BEC = BE reactant - BE product
If pos-endo
If neg-exo
Endothermic explanation for bond forming
Energy needed to break bonds if greater than energy releases forming bonds
Exothermic explanation bond making
Energy releases forming bonds is greater than energy needed to break bonds
Concentration =
Mol/ volume
Conc unit
Mol/dm3
Mol / dm3 =
Mol / dm3
Mol / volume
dm3 to cm3
X 1000
Mol / dm3 to g / dm3
X Mr
Concentrations in equilibrium?
Remain constant not the same
