Calculate the number of kilojoules to warm 125 g of iron from 23.5 °c to 78.0 °c.

120,630,890

step-by-step explanation:

110+10=120,620+10=630,880+10=890

u i forgot the answer?

the answer is b & c i believe : )

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