Question

How many atoms are contained in the chemical formula `2AgNO_3`?

Answer 1

In one silver nitrate formula unit, there are 3 oxygen ATOMS, 1 nitrogen ATOM, and 1 silver atom.

Explanation:

Quite clearly, in 2 formula units of silver nitrate, there are 2 silver atoms, 2 nitrogen atoms, and 6 oxygen atoms.

We can improve this answer by using the mole concept. The mole is simply a VERY large number: `N_A= 6.022xx10^23`.

If we have 2 moles of silver nitrate, there are `N_A` silver atoms, `2xxN_A` nitrogen atoms, and `6xxN_A` oxygen atoms. Using the molar masses of each element, we can therefore predict the MASS of a mole of silver nitrate as `169.87` `g*mol^-1`, where this mass is the sum of the individual molar masses of the constituent elements.