Question

If a mole of C$_3$H$_8$ is reacted with 2.5 moles of O$_2$ how many moles of H$_2$O will be produced ?

• A. 1 mole of H$_2$O
• B. 2 moles of H$_2$O
• C. 3 moles of H$_2$O
• D. 4 moles of H$_2$O

Hint:

Use stoichiometric coefficients from balanced reactions to relate moles of reactants and products.

Answer 1

The Correct Option is B

Balanced equation: C$_3$H$_8$ + 5O$_2$ → 3CO$_2$ + 4H$_2$O
From 5 moles of O$_2$, 4 moles of H$_2$O form. So, 2.5 moles of O$_2$ will form: \[ \frac{4}{5} \times 2.5 = 2\, \text{moles of H}_2\text{O} \]