Molar mass is defined as the mass of one mole of its atoms. It is generally expressed in g/mol.
We must also take into account that in a mole of substance there are 6.0221x10^23 particles.
To calculate the molar mass of a molecule we must add the atomic weights of the elements involved and multiply them by the number of atoms of the element, that is, we make an average of the atomic weights.
If we see, all the options that they give us, refer to a mole or its molar mass, but they ask us specifically what mass the molar mass refers to, and the answer is that this mass refers to a mole of a substance.
And all the options that we are given, talk about one mole of a substance, so all the options given apply.
Answer:
• the g/mol of a substance
,
• 6.0221 x 10^23 particles of a substance
,
• the mass of a substance per mole
,
• the average atomic mass units