With all his gear, neil armstrong weighed 360 pounds on earth. when he landed on the moon, he weighed 60 pounds. why?
a his mass changed while traveling to the moon.
b. the gravity on the moon is six times the gravity on earth.
c. the gravity on the moon is less than the gravity on earth.
od. he experienced the effects of a gravity slingshot.

b. is the answer hoped i        

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