Question

What is the molar mass of lactic acid, ${C_3}{H_6}{O_3}$ ?

Answer 1

Hint : The molar mass of any chemical compound refers to the ratio of mass of a sample of that particular compound and the amount of substance in that particular sample (in moles). The molar mass is actually a bulk characteristic of a substance rather than molecular. The molar mass is generally represented as $gmo{l^{ - 1}}$ .

Complete Step By Step Answer:
The molar mass of any compound can be found out by adding the relative atomic masses of each element present in that particular compound. The number of atoms in a compound can be determined from their chemical formula.
Now, let us calculate the molar mass of the given compound i.e. lactic acid. The chemical formula of lactic acid is given i.e. ${C_3}{H_6}{O_3}$ We already know the atomic mass of carbon, hydrogen and oxygen which is mentioned below:
C = 12.0107u \\\ H = 1.00784u \\\ O = 15.9994u \\\
From the chemical formula, it is clear that lactic acid comprises of three atoms of carbon, six atoms of hydrogen and three atoms of oxygen and thus molar mass of this compound can be easily calculated by adding the mass of three carbon atoms, six hydrogen atoms and three oxygen atom as shown below:
Molar{\text{ }}mass{\text{ }}of{\text{ }}{{\text{C}}_3}{H_6}{O_3} = (3 \times C) + (6 \times H) + (3 \times O) \\\ = (3 \times 12.0107) + (6 \times 1.00784) + (3 \times 15.9994) = 90.07734gmo{l^{ - 1}} \\\
Hence, the molecular weight of ${C_3}{H_6}{O_3}$ is 90.07734 $gmo{l^{ - 1}}$ .

Note :
Molar mass plays a significant role in chemistry especially during setting up an experiment. During testing principles which involve specific amounts or quantities of a substance, molar mass is used to figure out the exact quantity to be weighed of that particular substance. Basically molar mass is used to determine the stoichiometry in the chemical reactions as well as equations.