"How many moles of oxygen are required to react completely with 5 mol C(8)H(18)?"
2C(8)H(18) + 25O(2) => 16CO(2) + 18 H(2)O
In the question, how do I know if "oxygen" means the molecule O(2) or the element O?
http://www.jiskha.com/display.cgi?id=1285089963 as an example.
Oxygen refers to the diatomic molecule, O2.
But if the question wanted me to find the moles of O, how would it be phrased? Thanks
It would ask, moles of the oxygen free atom, O.
In this context, "oxygen" refers to the element O₂, commonly known as molecular oxygen. In chemical reactions, oxygen is typically represented as O₂ because it naturally exists as a diatomic molecule.
To determine the number of moles of oxygen required to react completely with 5 moles of C₈H₁₈, we can refer to the balanced equation you provided:
2C₈H₁₈ + 25O₂ → 16CO₂ + 18H₂O
According to the equation, for every 2 moles of C₈H₁₈, we need 25 moles of O₂ to react completely. To find the moles of oxygen required for 5 moles of C₈H₁₈, we can set up a proportion:
2 moles C₈H₁₈ / 25 moles O₂ = 5 moles C₈H₁₈ / x moles O₂
Solving for x, we multiply both sides of the equation by x and divide by 2:
(5 moles C₈H₁₈ * x moles O₂) / 2 moles C₈H₁₈ = 25 moles O₂
Cross-multiplying, we get:
5x = 2 * 25
Simplifying, we find:
5x = 50
Dividing both sides by 5, we get:
x = 10
Therefore, 10 moles of O₂ are required to react completely with 5 moles of C₈H₁₈.