Question

how many moles of oxygen atoms are contained in the following?1.67 x 10-2mol CuSO4-5 H2O

Answer 1

I dont understand this CuSO4-5 H2O. Could you write it in another way?

Answer 2

\(\huge CuSO_4•5H_2O\)

Answer 3

there is a simple way of solving it
1. Calculate molecular mass of CuSO4•5H2O
2. Calculate molecular mass of ALL oxygen atoms in CuSO4•5H2O (which are 4 oxygen atoms in CuSO4 and 5 oxygen atoms in H2O so in total its 9 oxygen atoms, thus find molecular mass if 9 oxygen atoms)
3. Do mathematical cross multiplication

Molecular mass of CuSO4•5H2O - \(1.67 \times 10^{-2}moles\)
molecular mass of 9 oxygen atoms - X moles

so
X= \(1.67 \times 10^{-2}moles\) * molecular mass of 9 oxygen atoms / Molecular mass of CuSO4•5H2

and get the answer :3

Answer 4

X=(0,0167mol(CuSO45H2O) x 9,00mol(O))/1,00mol(CuSO45H2O)=0,153mol

Answer 5

oh correction at the end i forgot O in H2O
sorry :>

Answer 6

btw its not 9 mole of O
its molecular mass of 9 O atoms
which means 1 O atom is 16 g/mole so 9 of O atoms is 9*16= ....g/mol of O atoms
this is total molecular mass of O atoms in that compound

Answer 7

molecular mass of CuSO4•5H2O also can be found same way using periodic table and number of each atom in this compound.

Answer 8

let's say that you have 1 mol of the compound, that will be 6.02xE+23 molecules, hence there are 6.023xE+23 x(9) molecules of oxygen, that is 9 moles.

Answer 9

erm im asking for atomic mass
not number of atoms as in using Avogadro constant
lets say O2
O2 consists of 2 O atoms bonded together
when we are asked for its molecular mass (atomic mass) then atomic mass of 1 O atom is 16 g/mole
but O2 has 2 O atoms so
16*2= 36 g/mole is atomic/molecular mass of this compound O2

Answer 10

i don't exactly know how to explain this as you guys learnt it in different way so you mix this up with moles
as molecules or atoms are not same as moles
but i'll try
look
number of moles of something * Avogadro constant= number of atoms
so
1mole of something * (6.02*10^23) = number of atom of that something
this means that 1 mole of that something contains 6.02*10^23 ATOMS
so that many atoms is in 1 MOLE
so when it comes to compounds
H2O for example
its not like there is 2 moles of H and 1 mole of O
its 2 ATOMS of H and 1 atom of O!
so you cannot take it as mole! coz mole and atom are different things!
mole consists if particular number of atoms
but atoms don't consist of moles
so don't mix up

Answer 11

what when you say 1 mol of water that means that there are 6.023xE+23 molecules, hence there are 6.02xE+23 atoms of oxygen because each molecules of water has one atom of oxygen, that's 1 mol of oxygen.

Answer 12

and who said that its 1 mole of H2O?
this is the thing, it is not given how many moles of H2O are there
thus you don't need to focus on that
you can find mole after you balance the equation from which you get H2O
using formula mole=mass/ molecular mass
(thats just an example)

Answer 13

lets say i just gave you a sample of H2O
its just some amount
thus you don't know how many moles is that
so you cannot say that you are given 1 mole if H2O

Answer 14

of*

Answer 15

i did not say that's the amount that we have, it was an example.

We can't say that it is 1 mol , but it works to find the proportion that will give us the answer.

Answer 16

idk probably works
but i don't like mixing it whatsoever so i just go with my way :3