The decomposition of hydrogen peroxide has the tate law: k (H₂O2). The rate constant is 1.06×10^-3
long will it take for the concentration of hydrogen peroxide
to drop from
0.020omol per dm^3 to 0.0120 mol per dm^3​

gold is my favorite solid.

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