quantitive chemistry (paper 1) Flashcards
moles equation
mass
——————————-
relative formula mass
steps for reacting mass calculations
highlight the unknown and unknown
workout no. of moles for the known substance
divide the moles of the known by the number in-front of the known
multiply by the no. in-front of the unknown
workout the mass for the unknown substance
Avagadros constant
number of atoms or molecules =
moles x 6.02 x 10^23
mass of one atom equation
mass of one mole
————————
Avagadros constant
how to work out uncertainty
range
———
2
eg +
- 8
using moles to balance equation steps
add the substances from the question
divide the masses from the question (GRAMS) by the mr of the substance
work out no. of moles for each substance
work out the simplest ratio - look for the smallest number of moles and divide each number of moles by it
limiting reaction steps
fill in reacting moles from the equation
fill in moles from the question
you can’t use the product in excess to work out the reaction
equation for percentage yield
mass of actual product
———————————. X100
maximum theoretical mass
volume of gas equation and units
moles x 24
3
measured in dm
which is the only equation where you use the big numbers infront in the equation
atom economy
key properties of nano particles
very small size
high surface area to volume ratios
uses of nano particles
in suncream - nanoparticles of zinc oxide can can block harmful ultraviolet light
concentration equation (g/dm^3)
mass of solute
———————
volume of solvent
concentration equation (mol/dm^3)
number of moles of solute
————————————
volume of solvent
atom economy equation
relative formula mass of desired
———————————————. X100
relative formula mass of all reactants
