AOS Flashcards
Avogadro constant definition
Number of atoms in 12g C12
Number of particles equation
Moles x avagardos constant
Ar definition
Average mass of an atom of an element/ 1/12th the mass of C12
Percentage yield
Actual yield/theoretical yield x100.
Importance: Increases the amount of product that is made from the reactants, can be increased by making improvement in experimental technique.
Atom economy
mass of desired product/ total mass of reactants x100
(mr/mr x100)
Standard solution
Transfer known mass of solid. weigh sample bottle cotaining solid on a balance. Transfer the beaker to re-weigh sample bottle. record difference in mass. Dissolves in water, add distilled water, stir with a glass rod, until all has dissolved. Transfer to volumetric flask using funnel with washings, make up to 250cm^3. Invert to mix
Titration accuracy
- remove any air bubbles- volume will be counted in burette reading
- remove funnel- solution drops could fall from funnel into burette affecting burette reading.
- rinse with distilled water- ensures all reactants mix and no reagent is unreacted. Moles remains the same.
Percentage error
error of equipment/ amount measured x 100
How to reduce it: Increase the concentration of solution in conical flask, decrease conc of solution in burette.
Ideal gas equation
Pv=nRT