1 mole of substance is equal to atomic/molecular mass in grams? I have been reading the answer of this question here- Why is weight of 1 mole of substance equal to atomic/molecular mass in grams



I feel that the answer writer was wrong to say that -"the ratio of g/mol to amu/atom is exactly one"

I  feel so because he proved that the ratio of g/mol C12 to amu/atom C12 is exactly one.He never proved that the ratio of g/mol to amu/atom is exactly one.If I am wrong then please correct me!
The statement is more or less correct.

But there are two caveats here:


There is no proving of these concepts since there are definitions.
In general, it's a bit strange to use the ratio of amu to atom. An atom has a well defined mass based on it's isotope, but the number of grams per mole is defined based on natural abundance and weighted average mass. Therefore, there is some discrepancy here. Of course, here, you're referring specifically to carbon-12, so there is no confusion, but just watch out in the general case.