Amount of Substance Flashcards
What is the atom economy equation?
Mr of desired product/Mr of all products x100
What is the percentage yield equation?
actual yield/theoretical yield x 100
What are reasons for percentage yield being less than 100%?
incomplete reaction, side reactions, loss of product during washing or transferring
What is the equation for density?
D=m/v
How do you work out theoretical yield?
mols of reactant, mole ratio, use theoretical moles to work out theoretical mass
What is the percentage purity formula?
mass of pure substance / mass of impure sample x 100
How do you find concentration?
moles/volume
How do you make a volumetric solution?
Transfer known mass of solid using weighing boat, add approx 100cm3 of deionised water to beaker and stir with glass rod until dissolved, transfer solution to volumetric flask using funnel, rinse beaker stirring rod and funnel with deionised water and transfer into volumetric flask, add deionised water to flask to make up to graduation mark use dropping pipette when close to mark, invert flask to make sure it’s thoroughly mixed
What colour is phenolphthalein in acid and alkalis?
acid- colourless alkali- pink
Why is a conical flask used instead of a beaker?
it is easier to swirl the mixture without spilling the contents
What is the equation for practical errors?
Margin of error/ quantity measured x100
What is the ideal gas equation?
PV=nRT
What are the units for the ideal gas equation?
pressure (Pa), Volume (m3), number of moles, R (8.314 JK-1mol-1), Temperature (K)
How do you convert Celsius to Kelvin?
add 273
