Question

84.27 grams of hexane combusts with excess oxygen to form carbon dioxide and water. What mass of water in grams will be produced?

Answer 1

The reaction will produce 123.4 g of water.

Explanation:

1. Write the balanced equation.

`"2C"_6"H"_14 + "19O"_2 → "12CO"_2 + "14H"_2"O"`

2. Calculate the moles of `"C"_6"H"_14`.

`"Moles of C"_6"H"_14 = 84.27 color(red)(cancel(color(black)("g C"_6"H"_14))) × ("1 mol C"_6"H"_14)/(86.17 color(red)(cancel(color(black)("g C"_6"H"_14)))) = "0.977 95 mol C"_6"H"_14"`

3. Calculate the moles of `"H"_2"O"`.

`"Moles of H"_2"O" = "0.977 95" color(red)(cancel(color(black)("mol C"_6"H"_14))) × ("14 mol H"_2"O")/(2 color(red)(cancel(color(black)("mol C"_6"H"_14)))) = "6.8457 mol H"_2"O"`

4. Calculate the mass of `"H"_2"O"`.

`"Mass of H"_2"O" = 6.8457 color(red)(cancel(color(black)("mol H"_2"O"))) × ("18.02 g H"_2)/(1 color(red)(cancel(color(black)("mol H"_2"O")))) = "123.4 g H"_2"O"`