Noob Q

[T3l3port]

M(CuSO4.5H2O)

where M stands for molar mass..

I've had a mental blank but does the 5 in front mean 10 H and 5 O or 5 of H20

[taiga]

yeah it means 10 H's and 5 O's if you are talking about molar mass; definitely not year 7 though.

On the other hand, it means it is hydrated by 5 moles of water for every 1 mole of Copper sulfate.

[DNAngel]

5 in front could mean 10 H and 5 O

Or

5 H20 molecules

You should get a molar mass of 90 gmol^1 for 5H20

[T3l3port]

M(CuSO4.5H2O) = (1 × 63.54) + (1 × 32.064) + (4 × 15.994) + (5 × 18.01)
= 250 g mol–1

That's the answer.

By that the 5 means 5 of H20.

I'm confused

[taiga]

If you are talking about molar mass;  5 of H20 is exactly the same as having 10 of Hydrogen and 5 of Oxygen.

[T3l3port]

If you are talking about molar mass;  5 of H20 is exactly the same as having 10 of Hydrogen and 5 of Oxygen.

Makes sense! So if it's not molar mass the 5 does matter? What is it 'technically' do? (the 5)

[taiga]

This is talking about hydrated copper sulfate.

Dehydrated copper sulfate looks something like this;


Hyrdrated copper sulfate (the one we are talking) looks like this;


As to what the difference is; I haven't studied anything higher than VCE chem so perhaps someone like Mao can tell you. To my knowledge it definitely causes a colour change

I think it makes it more suitable for storage (i maybe wrong) as atmospheric water can hydrate it and cause for errors in any calculations you are making because you would think that you had a certain number of mols of Copper Sulfate given the mass, but in reality, a lot of it is water. So having it hydrated probably means that the effects of the atmosphere will be lesser on any calculations you are making.

[T3l3port]

^

I appreciate your description but I didn't want a difference between the two compounds.

I want to know the technical meaning of the '5' (what does it do?)

Does it make H >> 5H ?

Or does it make H20 >> 5H20 ?

[Water]

^

I appreciate your description but I didn't want a difference between the two compounds.

I want to know the technical meaning of the '5' (what does it do?)

Does it make H >> 5H ?

Or does it make H20 >> 5H20 ?

It basically means 5 moles of H2O, given that one H2O is 1 mol

So instead of having 1 piece of H2O, you have 5 pieces of H2O?



Say, you have 1 apple, then      you suddenly get the quantity of 5 times the amount of apples.

And lets say Apples Formula is ABC



Then for every component in A B C, there would also be 5 times amount in it as well.


Its just a measure of ratio.



PS: And When your calculating between the Copper Sulphate and Water, you'd  compare the ratio between Copper Sulphate and Water



So CuSO4 has an invisible one in front of it.



And there is 5x of H2O



So take CuSO4 as Oranges


And H2O as Apples


You'd have 5x the amount of Apples than Oranges as the ratio is 1 : 5


Quite basic, but it'll get harder,  and you shouldn't expand the 5 into H2O as taiga said below, you'll get a different chemical formula. quite different from that of H2O. IT JUST MEANS THERES 5x THE AMOUNT OF pieces in WHATEVER THAT IS.

Eg, you can't have 5 times expanded into Apples, it doesn't make anything.

[taiga]

hahaha my bad i just wanted to put in cool pics LOL

It makes H2O >> 5H2O ; I would definite not write H10O5; as in some rare cases you might end up with a different chemical alltogether!

It just means that there are 5 Water Molecules in it, as opposed to just the one before.

[iNerd]

Wow this help me aswell - we starting the mole.

Good Q t3l3port - noob for me too!

[T3l3port]

Ah, thanks guys!

@ATAR: Np - this mole shiz is confusing!