The balanced chemical equation for the reaction between pcl5 and water is given below. if 3.45 moles of hcl are produced, how many moles of water reacted? pcl5(aq) + 4 h2o (l)→h3po4(aq) + 5 hcl (aq)

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