Foundations? Flashcards
What does anhydrous mean?
Without water
What does every hydrated salt contain?
Specific number of water molecules
How do you write the hydrated salts?
With a dot to show they’re with water
E.g. MgSo4.7H20
What are the assumptions with water of crystallisation?
1: all water has been completely evaporated
2: there is no further decomposition
What is atom economy?
The percentage of atoms that are in the useful product
What is the formula for atom economy?
(With stoichiometry) (mr of useful product / total mr (either reactants or products) x 100
How do you work out percentage yield?
Actual yield (given) / theoretical yield (use reacting masses) x 100
What is a salt?
An ionic compound formed from an acid when the H+ ion is replaced by a metal ion or NH4+
What is neutralisation?
H+ ions from an acid react with a base tp form a salt and water
Exceptions of NH3
What is the method for and acid-base titration?
1) Add measured volume of one solution to a conical flask using a pipette
2) Add other solution to a burette and record the initial butte reading to nearest +-0.05cm3
3) Add a few drops of indicator or solution in conical flask
4) Run solution in the Burnett into the solution in the conical flask while swirling to react all particles fully
5) Indicator changes colour at the end point of reaction which indicates the volume of one solution exactly reacts with the volume of the other
6) Record final burette reading and calculate the titre value
7) Carry out trial titration to find approx
Image titre
8) Repeat titration accurately. Add solution in droplets towards the end point
9) Continue unit, two concordant results
Definition of titre?
Volume of solution added form burette
