Question

Question #407ab

Answer 1

We know that `N_A` ammonia molecules have a mass of `17.03*g`. And thus the number of atoms in a `4.25*g` mass of AMMONIA is `6.01xx10^23`, i.e. `"Avocado's number of atoms."`

Explanation:

We work out (i) the molar quantity of ammonia:

`=(4.25*g)/(17.03*g*mol^-1)=0.250*mol`

And (ii), we were axed for the number of ATOMS in such a molar quantity. And because there are 4 moles of atoms in EACH mole of ammonia, we get a mole of atoms as our final answer....

... `0.75xxN_A` `"hydrogen atoms"` `+` `0.25xxN_A` `"nitrogen atoms"`.

i.e. a mole of atoms in TOTAL.