Read the given chemical reaction.

C2H6 + O2 → CO2 + H2O

How many moles of H2O are produced during the complete combustion of 1.4 moles of C2H6?

The answer to your question is 4.2 moles of H₂O

Explanation:

Data

moles of H₂O = ?

moles of C₂H₆ = 1.4

Balanced chemical reaction

               2C₂H₆  +  7O₂   ⇒   4CO₂   +  6H₂O

Process

To determine the moles of H₂O, use proportions and the coefficients of the balanced chemical reaction.

              2 moles of C₂H₆ 6 moles of H₂O

             1.4 moles of C₂H₆  x

                                  x = (1.4 x 6) / 2

                                  x = 8.4/2

                                  x = 4.2 moles of H₂O

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

the correct answer would be b) volume versus temperature, because they are also directly proportional.