if one pound (454g) of hexane combusts how many grams of water are produced?
my work: 454 g C6H14 * 1 Mol C6H14/86 g C6H14 * 7H20/1 mol C6H14 * 18 g O2/ 1 MOL H2O = 665.2 grams of H2O
This looks ok but you have too many s.f.. I would round that answer to 665 g.
Your calculations seem to be off. Let's break down the steps to correctly find the number of grams of water produced when one pound (454g) of hexane combusts.
Step 1: Convert grams of hexane to moles of hexane.
454g of hexane * (1 mol hexane / 86 g hexane) = 5.279 mol hexane
Step 2: Determine the stoichiometric ratio between hexane and water in the balanced chemical equation:
2 C₆H₁₄ + 19 O₂ → 12 CO₂ + 14 H₂O
According to the equation, 2 moles of hexane produce 14 moles of water.
Step 3: Convert moles of hexane to moles of water.
5.279 mol hexane * (14 mol water / 2 mol hexane) = 36.574 mol water
Step 4: Convert moles of water to grams of water.
36.574 mol water * (18 g water / 1 mol water) = 657.332 g water
Therefore, when one pound (454g) of hexane combusts, approximately 657.332 grams of water are produced.