Question

 If you mixed three plastic cup's contents containing 0,05 L of 1M Kool-Aid, 0.05 L of 2.5M Kool-Aid, and 0.05 L of 0.5M Kool-Aid, what would the molarity be of the resulting solution?

Answer 1

M = 1.183

Molarity is moles/Liter, so setting up some equations gives you

1) 1M = Xmol/0.05L

2) 2.5M = Xmol/0.05L

3) 0.5M = Xmol/0.05L

Solve for each X

1) X = 0.05mol

2) X = 0.125mol

3) X = 0.0025mol

Now add all the moles and Liters (separately)

XM = (0.05+0.125+0.0025)mol/(0.05+0.05+0.05)L

XM = 0.1775mol/0.15L

X = 1.183M