What is the mass of –

(a) 1 mole of nitrogen atoms?

(b) 4 moles of aluminium atoms((Atomic mass of aluminium =27)?

(c) 10 moles of sodium sulphite (Na\(_2\)SO\(_3\))?

(a) Atomic mass of nitrogen atoms = 14u

Mass of 1 mole of nitrogen atoms= Atomic mass of nitrogen atoms

Therefore, mass of 1 mole of nitrogen atom is 14g

(b) Atomic mass of aluminium =27u

Mass of 1 mole of aluminium atoms = 27g

1 mole of aluminium atoms = 27g \(\Rightarrow \) 4 moles of aluminium atoms = 4 × 27 = 108g

(c) Mass of 1 mole of sodium sulphite Na\(_2\)SO\(_3\)
= Molecular mass of sodium sulphite
= 2 × Mass of Na + Mass of S + 3 × Mass of O
= (2 × 23) + 32 +(3 × 16) = 46 + 32 + 48 = 126g

Therefore, mass of 10 moles of Na\(_2\)SO\(_3\) = 10 × 126 = 1260g