Which object has the greatest velocity? Assume the objects have equal masses. - Object D, with 50 joules of kinetic energy.

- Object A, with 10 joules of kinetic energy

- Object C, with 30 Joules of kinetic energy

- Object B, with 20 joules of kinetic energy

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