How many millimeters (mm) is the length of a standard table if it is
measured to be 1.50 meters (m). Remember 1000 mm = 1 meter.

1,500 mm

Explanation:

if 1 meter = 1000 mm, 0.5 meters is 500 mm, so 1.50 meters is 1,500 mm

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