Question

Magnesium nitrate reacts with lithium sulfate in a double replacement reaction. You have 3.45 g of lithium sulfate and 275 mL of magnesium nitrate. Calculate the molarity of the Magnesium nitrate solution in the reaction.

Answer 1

Not possible to work, as I see it. 275mL of magnesium nitrate? How can one determine how much magnesium nitrate is there? is it in excess, or deficit, or exactly enough? One wonders.

Answer 2

welp that's what the problem is.

Answer 3

First I want to make it very clear that Mg(NO3)2 and Li2SO4 will NOT react at all and it is folly to try to calculate the M of the Mg(NO3)2 this way. However, the calculation can be done (although it doesn't man anything)so in the spirit of chemistry I will continue.
Mg(NO3)2 + Li2SO4 ==> MgSO4 + 2LiNO3

moles Li2SO4 = grams/molar mass = ?
Using the coefficients in the balanced equation, 1 mol Li2SO4 reacts with 1 mol Mg(NO3)2 so mol Li2SO4 = moles Mg(NO3)2
M Mg(NO3)2 = moles Mg(NO3)2/L Mg(NO3)2