Question

$C_3{H}_8\left(g\right)+5O_2\left(g\right)\to 3C{O}_2\left(g\right)+4H_{2}O\left(l\right)$
Grams of water required for complete combustion of $44.0$ grams of propane for the equation given?

• A. $4.50g$
• B. $18.0g$
• C. $44.0g$
• D. $72.0g$
• E. $176g$

Answer 1

Answer: (D)

$72.0g$

The molar mass of propane is $44.0g/mol.$
44.0 grams of propane corresponds to 1 mole.
Complete combustion of 1 mole of propane will give 4 moles of water.
The molar mass of water is $18g/mol.$
4 moles of water corresponds to $4mol\times 18g/mol=72.0g$ of water.