c5.1 monitoring chemical reactions Flashcards
factors when determining a reaction pathway
yield atom economy usefulness rate of the reaction equilibrium position
rate of reaction and reaction time relationship
it is inversely proportional
1/ reaction time = rate of reaction.
what affects the percentage yield
the reactant may react differently than expected
the reaction may not go to completion
you may lose some of the products when separating it from the reaction mixture to purify it
atom economy
formula mass of desired product/ formula mass of all products * 100
cm3 to dm3
divide by 1000
titrations (6 marker)
- put a known volume of alkali into a conical flask
- add a few drops of indicator
- then add acid using a burette, until the indicator changes colour.
- repeat the experiment using the known volume of acid until you get at least 2 concordant titres
what colour is phenolphthaelin in acid and alkali
acid- colourless
alkali- pink
how can you make a titration more accurate
- use a volumetric pipette to measure the volume of alkali
- use a burette for the acid
- the burette should be clamped vertically
- swirl the flask
- keep a white tile underneath to see any colour change
- your first titre is usually a rough run so ignore it
safety for a titration
wear eye protection and gloves too
make sure the clamps are put on correctly and cant fall off
what is molar volume
one mole of substance in the gas state occupies the same amount of volume at the same temperature and pressure. for a gas it is :
24 dm3/mol
volume of a gas equation
volume (dm3) = amount in mol * 24 dm3/mol