Given that a substance has a specific heat of 3.77 J/g•°C, what mass (in grams) of it would be required if the release of 245 J of heat energy was desired when it is cooled from 69.6°C to 48.5°C?

your answer would be a. 12.5 kg

- decrease the number of plants and animals living in the water.

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