What are the factors that could cause the calculated molecular weight to be low?
If you are trying to calculate the molecular weight first you should be careful about your molecular formula because sometimes parenthesis es can be tricky for example Ca(NO3)2 has 1 Ca 2 N and 6 O. So meolecular weight of this compound would be MW= (1*Atomic weight of Ca)+(2*Atomic weight of N) +(6*Atomic weight of O) you should look at to the periodic table to find atomic weights second when you are using the atomic weights from periodic table you should also consider decimals.
