Question

What mass of B5H9 is needed to react completely with 0.750 gram O2 according to this equation?

2 B5H9 + 12O2 -> 5 B2O3 + 9H2O

ANSWER CHOICES:

		3.94 g
		0.247 g
		5.72 g
		6.08 g
		84.0 g
		4.51 g
		3.06 g
		13.6 g

Answer 1

Answer

The given chemical reaction is

2 B5H9 + 12O2 -> 5 B2O3 + 9H2O

Here 2 moles of B5H9 completely react with 12 moles of O2 to produce 5 moles of B2O3 and 9 moles of H2O

We know that the molecular weight of the compound B5H9 and O2 are 126.24 g/mol and 31.998 g/mol respectively

Since

126.24 g of B2H9 completely react with 383.976 g of O2

'X' g of B2H9 completely react with 0.750 g of O2

Therefore

'X' = (126.24 x 0.750 ) / (383.976)

'X' = 0.247 g of B2H6

Therefore 0.247 g of B2H9 completely react with 0.750 g of O2

Therefore 0.247 g option is correct option