Molarity Question

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[Zell]

Hey everyone! I'm having trouble with the following question:

Tell whether it is possible to make a 1.0 M solution at 0 degrees C?
a) CuSO₄ x 5H₂O, solubility = 23.1g/100mL
b) AgNO₃, solubility 122g/100mL

I don't know how to begin or work through this problem. Thanks in advance!

[Otis]

1.0 Molar solution is 1 mole solute in 1 liter solvent

23.1 gram CuSO4-5H2O in 100mL is 231.g in 1 Liter
     Is 231 more or less than one mole.

Same thinking for silver nitrate.

Otis

[valdorod]

I was thinking that the question was trying to trick you into thinking that at 0^o C water would be frozen thus making you think that you cannot make a solution since water would not be in a liquid state.

If the question is "can" you make a solution at 0^oC? If the water is already frozen, the answer is no.  If it is just beginning to freeze, then the answer is yes.

If the question is can you "have" a 1.0 M solution at 0^oC?  Then the answer is yes, because a 1.0M molar aqueous solution would freeze at a temperature of -1.86 ⁰C or lower depending on the type of solute due to colligative properties.

[Otis]

Colligative properties, or a poor "contrived" question. Profs and their of the cuff questions.

Otis

[Zell]

Thanks a lot guys!!! ^^