7. 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 (Na2SO3)?
Answer:
Atomic mass in gram represents one mole of that substance.
So,
a) the mass of 1 mole of nitrogen = 1* amu in gram = 1* 14 = 14 gm.
Similarly,
b) 4 mole of aluminium atom = 4* 27 = 108.
c) 10 mole of sodium sulphite = 10* weight of 1 mole of sodium sulphite
= 10((2*23) + 32 + (3*16)) = 10*126 = 1260.
Next: Question 8: Conversion of mass into the mole.
See also: Calculation of molar mass.
