Measuring volume by displacement is A. finding the volume of an object with a ruler.
B. finding the amount of matter in an object with a
scale.
C. finding the volume of an object by pushing liquid
aside.
D. finding volume of an object by using a scale.

pv=nrt

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

a physical change biology

explanation: