160 grams of sodium nitrate is dissolved in 100 cm^3 of water at 90*c. When the solution cools to 60*, some of the salt settles out in the bottom of the beaker. The salt settles out because the solution is now saturated
unsaturated
oversaturated
supersaturated

your answer would be “dry”

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