Question

If 10.0 g of substance X dissolved in 100 mL of solution, and the molarity of the solution is 1.0 M, what is the molar mass of substance X?

1000 g/mol
10 g/mol
1 g/mol
100 g/mol

Answer 1

M X = mols X/L. You know M and L, solve for mols X
Then mols X = grams/molar mass. You know grams and mols, solve for molar mass X.

Answer 2

100?

Answer 3

yes