3. 0.30 moles of Br2 (g) and 0.30 moles of Cl2(e) are introduced into a 1.0 L container at 400 K. The equilibrium constant for the reaction
Br2(g) +Ch() +2BrCle)
is Ko= 7.0 at this temperature. Calculate the equilibrium concentrations for
each of the species in this system.

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

answer carbon and three oxygen atoms;