Kasterville is a rapidly growing city. which of the following situations will most likely have a positive impact on the resources available to kasterville? a. factories dump wastewater directly into nearby rivers. b. builders cut down trees to build homes without replanting new ones. c. most people water their lawns every day to keep them green. d. most people are careful to recycle all glass, metal, and plastic.

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