Question

In the equation:

2H2 + O2 --> 2H2O

What mass of Hydrogen Gas will completely react with 4 moles of Oxygen gas

(Hint: going from moles to mass of another compound)
A)8 g
B)16 g
C)24 g

Answer 1

Answer:

B) 16 g

Explanation:

• 2H₂ + O₂ → 2H₂O

First we convert 4 moles of O₂ into moles of H₂, using the stoichiometric coefficients of the balanced reaction:

• 4 mol O₂ * $\frac{2molH_2}{1molO_2}$ = 8 mol H₂

Finally we convert 8 moles of H₂ into grams, using its molar mass:

• 8 mol H₂ * 2 g/mol = 16 g

Thus, the correct answer is option B).