Answer:
0.0249 moles in 1 g of Ca
Explanation:
Let's think in the molar mass of Ca.
Ca = 40.08 g/mol
So 1 mol weighs 40.08 grams, or in the opposite 40.08 grams is the weigh of 1 mol
The rule of three will be:
40.08 g are contained in 1 mol
1 g may be contained in (1 . 1) / 40.08 = 0.0249 moles
The answer to your question is : no.of moles of Si = 43/atomic mass of Si = 43/28.1 = 1.53
according to reaction 3 moles of Si gives 1 mole of Si3N4
so 1.53 mole of Si will give 1.53/3 = 0.51 mole of Si3N4
molar mass of Si3N4 = 140.28 g/mole
it means that 1 mole of Si3N4 = 140.28 g
so 0.51 mole of Si3N4 = 0.51 X 140.28 = 71.543 g