Question

1)calculate the no, of molecules of 0.25 moles of ammonia ( NH₃).
2) calculate the no.of moles in 8.066 x 10²³ no. of nitrogen atoms.

Answer 1

1) 1 mole of NH₃ contains = 6.022$\times$10²³ molecules
0.25 moles contains = $6.022\times {10}^{23}\times 0.25$ = 1.50$\times$10²³ molecules

2) 6.022$\times$10²³ nitrogen atoms contain = 1 mole
8.066$\times$10²³ atoms = $\frac{1}{6.022\times {10}^{23}}\times 8.066\times {10}^{23}$ = 1.33 moles of nitrogen atoms