What is the molar ratio between water and oxygen, given the following equation? 2c4h10 + 13o2 -> 8co2 + 10h2o

a. 10: 2
b. 10: 13
c. 2: 13
d. 8: 10

B. 10:13

Explanation:

It is clear from the following balanced equation:

13 mole of oxygen (O₂) react with butane (C₄H₁₀) to give carbon dioxide (CO₂) and 10 moles of water (H₂O).

∴ The molar ratio between water and oxygen = (no. of moles of water : no. of moles of water) = (10:13)

So, the right choice is:

B. 10:13

answer: the enthalpy of the overall chemical reaction is +87.88 kj or +88 kj.

according to hess's law, the overall enthalpy of a reaction is the difference between the sum of enthalpy values of all the products and the sum of enthalpy values of all the reactants.

δh(reaction) = ∑nδh(products) - ∑nδh(reactants)

δh(reaction) = [δh +δh] - [δh]

δh(reaction) = [1(-287.02) + 1(0) ] - [1(-374.9)] kj = +87.88 kj

here, δh (pcl3) = -287.02 kj, δh(cl2) = 0, δh(pcl5) = -374.9 kj

therefore, enthalpy of the overall reaction is +87.88 kj or +88 kj.