Question

What is the mass in grams of one molecule of ethnic acid `CH_3COOH`?

Answer 1

`9.96181xx10^(-23)g`

Explanation:

1 mole of the organic carboxylic acid ethanoic acid (acetic acid) has a mass equal to its molar mass `M_r=12+3+12+16+16+1=60g//mol`.

But 1 mole contains an Avagadro number of molecules, ie `N_A=6.023xx10^23` molecules.

Therefore 1 molecule of this weak acid has a mass of `60/(6.023xx10^23)=9.96181xx10^(-23)g`