2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is

Question

2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is (A) -3.77 (B) -1.79 (C) -100.5 (D) none of these

Tardigrade Admin · Accepted Answer

Heat of formation = Energy evolved /mol Number of moles of Fe combining =(2.1/56)=0.0375 So total moles of FeS forming = 0.0375 Heat of formation =(-3.77/0.0375)=-100.5 kJ/mol

Q. 2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is

$- 3.77$

$- 1.79$

$- 100.5$

none of these

Heat of formation = Energy evolved /mol Number of moles of Fe combining $= \frac{2.1}{56} = 0.0375$
So total moles of $F e S$ forming $= 0.0375$
Heat of formation $= \frac{- 3.77}{0.0375} = - 100.5 k J / m o l$

Q. 2.1 g of Fe combines with S evolving 3.77 kJ. The heat of formation of FeS in kJ/mol is

−3.77

−1.79

−100.5

none of these

Heat of formation = Energy evolved /mol Number of moles of Fe combining =562.1​=0.0375 So total moles of FeS forming =0.0375 Heat of formation =0.0375−3.77​=−100.5kJ/mol

$- 3.77$

$- 1.79$

$- 100.5$

Heat of formation = Energy evolved /mol Number of moles of Fe combining $= \frac{2.1}{56} = 0.0375$
So total moles of $F e S$ forming $= 0.0375$
Heat of formation $= \frac{- 3.77}{0.0375} = - 100.5 k J / m o l$