Question

Gram molecular mass of $$C{H}_{3}OH$$ is:
a.) 28 g
b.) 16 g
c.) 32 g
d.) 62 g

Answer 1

Hint: Molecular mass of any compound equals the sum of atomic masses of all elements times their respective number of atoms.

Complete step by step solution:
The mass (in grams) of 1 mole of a molecular compound is called the gram-molecular mass of that compound. It is numerically equal to the molecular weight.

First we would have to find the individual atomic mass of each atom present.
In this case we need the atomic masses of Carbon, Hydrogen and Oxygen.

We know from the periodic table,
Atomic mass of Carbon = 12 grams
Atomic mass of Hydrogen = 1 grams
Atomic mass of Oxygen = 16 grams

Therefore molecular mass of can be calculated from the data we already have.
Molecular Mass of $$C{H}_{3}OH$$ is:
(1 x atomic mass of C) + (4 x atomic mass of Hydrogen) + (1 x atomic mass of Oxygen)
= (1 x 12) + (4 x 1) + (1 x 16)
= 12 + 4 + 16
= 32 grams

The Gram Molecular Mass of $$C{H}_{3}OH$$ is 32 grams (Option C).


Note: Gram molecular mass numerically the same as molar mass. The difference is that gram molecular mass specifies the mass unit to be used. For example: The molecular mass of $$N_2$$ is 28, so the gram molecular mass of $$N_2$$ is 28 g.