Answer: 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.
Explanation:
Given: mass of [tex]NH_3[/tex] = 56 g
Molar mass of [tex]NH_3[/tex] is 17.03 g/mol.
As moles of a substance are its mass divided by the molar mass. Therefore, moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of moles = \frac{mass}{molar mass}\\= \frac{56 g}{17.03 g/mol}\\= 3.28 mol[/tex]
According to the mole concept, 1 mole of every substance contains [tex]6.022 \times 10^{23}[/tex] molecules. Hence, number of molecules present in 3.28 moles of [tex]NH_3[/tex] are calculated as follows.
[tex]No. of molecules = no. of moles \times 6.022 \times 10^{23}\\= 3.28 mol \times 6.022 \times 10^{23}\\= 19.80 \times 10^{23}[/tex]
Therefore, we can conclude that 56 grams of gaseous ammonia (NH3), has 3.28 moles and [tex]19.80 \times 10^{23}[/tex] molecules.
