How much energy (in J) is lost when a sample of iron with a mass of 26.4 g cools from 74.0 ∘C to 26.0 ∘C?

Explanation:

Hello,

In this case, for the computation of the energy loss when the cooling process is carried out, we use the shown below equation:

Whereas we need the mass, specific heat and change in temperature of iron within the process. Thus, the only value we need is the specific heat that is 0.444 J/(g°C), therefore, we compute the heat loss:

Negative sign points out the loss due to the cooling.

Regards.

explanation:

0.07 g/cm³

1.37 g/cm³

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