(b) Calculate the molarity of the following solutions:
(i) 2.0 g CuSO4(s) in 100.0 cm3 water
(ii) 5.0 g Ca(OH)2 in 2 dm3 water
2007-01-08 02:22:29 · 3 answers · asked by jess_xx_2001 1 in Science & Mathematics ➔ Chemistry
work out the molecular mass (RMM)
Sorry I don't have a periodic table on me it's explained in my answer to your other question.
However these are the calculations you need:
Concentration (in moldm-3) = number of moles / volume in dm3 (cm3 divided by 1000)
number of moles = mass (in g) / RMM(g/mole)
2007-01-08 02:43:44 · answer #1 · answered by Ellie 4 · 0⤊ 0⤋
Add up the relative atomic mass of each atom (the larger numbers on the periodic table) in each of the compounds to give the relative atomic mass of each.
the relative atomic mass is the number of grams per mole of substance.
So you then get the number of moles by dividing the mass by the relative atomic mass.
The molarity is defined as number of moles per dm^3
so for the first one you would divide the number of moles by 0.1
2007-01-08 10:43:28 · answer #2 · answered by Mike 5 · 0⤊ 0⤋
are you doin AS chemistry. i have some old chemistry books from college. if you like i can send them.
2007-01-08 10:31:29 · answer #3 · answered by Anonymous · 0⤊ 0⤋