Interpret the following balanced chemical equations in terms of particles, moles, and mass. 1. Mg + 2HCl -> MgCl2 + H2
2. 2Al + 3CuSO4 -> Al2(SO4)3 + 3Cu
3. Cu(NO3)2 + 2KNO3

i'm pretty sure its b i might be wrong though!

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