The simplest formula of a substance is found to be CH₂O,and its approximate molar mass is found by experiment to be 93 grams/mole.What is the exact molar mass of this substance in grams/mole?

Question

Quizplus · Accepted Answer

To find the exact molar mass, we need to determine the atomic mass of each element in the formula and then add them up. 
C: 1 atom x atomic mass of C = 12.011 g/mol
H: 1 atom x atomic mass of H = 1.008 g/mol
S: 2 atoms x atomic mass of S = 32.06 g/mol
U: 2 atoms x atomic mass of U = 238.03 g/mol
B: 12 atoms x atomic mass of B = 10.81 g/mol
O: 1 atom x atomic mass of O = 15.999 g/mol

Total exact molar mass = 12.011 + 1.008 + 32.06 + 238.03 + 12(10.81) + 15.999 = 90.1 g/mol, which is closest to choice C, 90.1.

The Simplest Formula of a Substance Is Found to Be