A ball is thrown straight up (at 90° to the horizontal) and takes 5 seconds to return to the hand of the person who threw it after reaches its maximum height. How high is the ball above the launch point at its highest point?

"record the time to complete a chemical reaction" would most likely be part of a lab procedure.

d

explanation:

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

diaria maybe go see a doctor about that