3-step problem) How many grams of H2O are produced from 25.64 g of KNO2? Again, write out the equation and MAP it for this problem before attempting to solve---this is also a different map, with three steps! 5 KNO2 + 2 KMnO4 + 3 H2SO4  5 KNO3 + 2 MnSO4 + K2SO4 + 3H2O

the answer to your question is c

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