Question

a certain hydrate M.nH2O has 19% by weight of H2O in it the molar mass of M=230 g/mol calculate the value of n?? plz give the steps

Answer 1

is this multiple choice?

Answer 2

yes

Answer 3

i will give the options 2 6 3 4

Answer 4

i can t remember how to do this at the moment but, for some reason or another i am thinking it is 6

Answer 5

the answer is 3 but i dont know to do it......

Answer 6

Well, I am approximately getting 3.


Let T be the total mass of the salt

T = mass of water + mass of M
T = 18 n + 230 ------>(1)

Also
18n = (19/100) T ------->(2)

Solving (1) and (2)

I am getting n is apprximately 3

Answer 7

thanzz

Answer 8

i thought 230g/mol was the molar mass of M.nH_2O

Answer 9

@UnkleRhaukus , It is given molar mass of M=230 g/mol :)

Answer 10

is that the molar mass of the salt or the hydrated salt

Answer 11

M --> Molar mass of anhydrated salt :)

Answer 12

ok it is clear now

Answer 13

\[T-18n=230g/mol\]\[18n=19\%T\]\[ 81\%T=230g/mol\]\[T=\frac{230g/mol}{81\%}=284.0g/mol\]\[n.18g/mol=284g/mol-230g/mol=54g/mol\]\[n=\frac{54g/mol}{18g/mol}=3\]