c4 Flashcards
whats the formula for the number of moles
moles=mass(g) / Mr
whats the formula for working out mass (g)
mass=moles x Mr
what does Mr stand for
reltive formula mass
how do you figure out percentage mass
you find out the relative formula mass then divide the number by the relative formula mass
tell me the definition of yield
the mass of product that a chemical reaction produces
whats the equation of percentage yield
actual mass of product produced
——————————— x100
maximum theoretical mass of product possible
factors that may affect percentage yield
> the reaction may be reversible
> some of the product may be lost or left in the apparatus
> the reactants might not be pure
> some reactants might react to give unexcepted or unwanted products in alternative reactions
whats the formula for percentage atom economy
relative formula mass of the desired product from equation
——————————— x100
sum of the relative formula masses of the reactants from equation
why is it important to maximise atom economy in industrial processes
to conserve the earths resources and minimise population
how is atom economy usually expressed
as a percentage (%)
whats the formula for concentration for dm^3
amount of solute (g) /
volume of solution (dm^3)
what unit is a volume of solution normally
dm^3
whats the formula for concentration for cm^3
amount of solute (g)
—————————– x1000
volume of solution (cm^3)
whats the definition of a balanced equation
a symbol equation in which there are equal numbers numbers of each type of atom on either side of the equation
whats the formula for the number of moles in a gas for dm^3
volume of gas (dm^3)/
24dm^3
whats the formula for the number of moles in a gas for cm^3
volume of gas (dm^3)/
24,000cm^3
why does mass increase during a reaction
It has gained oxygen, and this has caused the increase in mass. This is why this is called an oxidation reaction.
after heating the crucible again what should you do to make sure the reaction is complete
Heat again, this time for 10 minutes, then cool and weigh as before. If the crucible, cover, and sample weigh the same, then we can be reasonably confident that the reaction is complete
