If 4.88 mol of ethane (C2H6) undergo combustion according to the unbalanced equation C2H6 + O2 → CO2 + H2O

how many moles of O2 is required?
How many moles of CO2 is formed?
How many moles of H2O is formed?
(Give answers in mol)

answer : third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol

explanation :

let us write down the given equations

equation 1 :

equation 2 :

equation 3 :

let us use hess's law to find out which 2 equations can be added to get the third equation.

let us reverse equation 2 and multiply it by 2. the new equation that we get is,

equation 4 :

let us add equation 1 & 4

the above equation is similar to equation 3 but has different value for dhrxn.

therefore third trial had the contaminated sample and the correct value for dhrxn should be 1000 kj/mol