Question

Consider the complete reaction of 43.0 g of silicon with excess nitrogen gas in the reaction shown below. What mass of product forms?3Si + 2N2 → Si3N4 Answer = _________ grams of product

Answer 1

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