Question

(A) A student performed the freezing point depression experiment according to directions but mistakenly recorded the mass of lauric acid as 8.300 g instead of 8.003 g. The calculated molar mass of the unknown acid will be ___________ than the true value, because the mass of lauric acid appears in the denominator of the unknown acid's molecular weight determination


A. less
B. greater

(B) therefore, if it was mistakenly recorded too high, it would ___________ the calculated moles of the solute.


A. decrease
B. increase

thanx

Answer 1

delta T = Kb*m.
m = mols/kg solvent.
molar mass = grams/mols.

Use the threee equatin above to answer both questions. I will do the first.
equations 1 and 2 are not needed for the first one. Using equation 3, if the quantity grams is too large, then g/mols will be too large, which will make molar mass too large. (Note: I don't get the statement at the end that the the " mass of lauric acid appears in the denominator of the unknown acid's molecular weight determination ." Where the mass of lauric acid appears (numerator or denominator) depends upon how I set up the equations.

Answer 2

its less and increase

Answer 3

less and increase just did it right now