# Homework Help: Hydrate Lab Help? PLEASE? DUETMRW><

1. Nov 13, 2008

### PrincessBoa

1. The problem statement, all variables and given/known data
Okay so I recieved this lab called Determining the Chemical Formula of a Hydrate, but I was not there to do it with my group..but I still had to answer these two questions. I was wondering if someone could help me answer them? >< Or explain?! ><

CuSO4 . xH2O

Materials:
400ml Beaker
tongs
scoopula
electronic balance
3 g to 5 g hydrated copper sulfate

QUESTIONS I NEED HELP ON

8. Suppose the hydrate was heated too quickly and some of it was lost as it spattered out of the container. Explain how this would affect

a) The calculated percent by mass of water in the compound. Does the mass/percent increase? What?!

b) The molecular formula you determined..CuSO4 5H20? O_O

9) Suggest a source of errot that would result in a value of x that is

a) higher than the actual value (How would it affect...like...a negative or something in the value of X? )
b) lower than the actual value.

THANKS

-PrincessBoa

2. Nov 14, 2008

### Staff: Mentor

Look at the formulas used for calculation. Some of them will be in the form of fraction. What happens when numerator is too big? Too smal? What in the case of denominator?

3. Nov 16, 2008

### PrincessBoa

I still sort of don't get it...o-o..\\

8. a) If the hydrate was heated too quickly, and some of it was lost or was splattered out of the container, this would drive out the water only leaving behind the copper sulfate anydrate CuSo4, which is white in color. This would decrease the calculated percent by mass of water in the compound.
b) The molecular formula would be CuSO4.
9) a) The source of error that would result in a value of x when it is higher than the actual value would be the copper sulfate would be too high, resulting in escaping water.
b) There would be too little water, not resulting in the proper equation which is CuSO4 . 5H20
?

HELP? ><