Tritrations (1 Viewer)

[mr_vocab]

could anyone please help me with this tritration questions

hom much copper sulfate pentahydrate would be needed to make up 200ml of a 0.2m solution. my min difficulty is in knowing what the formula for copper sulfate pentahydrate is and the equation i need to find the mole relationship/ratio

 

[rama_v]

could anyone please help me with this tritration questions

hom much copper sulfate pentahydrate would be needed to make up 200ml of a 0.2m solution. my min difficulty is in knowing what the formula for copper sulfate pentahydrate is and the equation i need to find the mole relationship/ratio

The formula for hydrate is just H₂O
So copper sulfate pentahydrate is just
CuSO₄.5H₂O

Then you find the number of moles in a 0.2 molar solution of 200ml, i.e. n = C * V (remember that V is in litres, so here V = 0.2)
You can then use the formula n = mass/molar mass to find the mass required

 

[Riviet]

A hydrate is a compound formed when in union with water, hence nH₂O, where n is the number of water molecules and is denoted by the prefix of its name. So Pentahydrate means 5 waters, therefore its formula is CuSO₄.5H₂O.

So the molecular mass (M) of CuSO₄.5H₂O is equal to:

63.55+32.1+64+10+16 = 185.65

number of moles of copper sulfate pentahydrate = cV = 0.2 x 02 = 0.04

.'. mass = n.M = 0.04 x 185.65 = 7.426g.

Keep in mind that you don't need to find any mole ratios or write out any equations, simply because we're only concerned with copper sulfate pentahydrate. Hope that helps.

 

[mr_vocab]

thanks alot for your help yeah i wasnt to sure what pentahydrate was, i hope that wont be in our practical test lol

nathan

 

[Riviet]

Glad to help, if it is in your test, then I'm sure you'll know exactly what to do.