If 0.523 mol of argon occupies a volume of 723 ml at a particular temperature and pressure, what volume would 0.735 mol of argon occupy under the same conditions?

The gas 0.735/0.523=1.405moles.

so 1.405 times of gas is present than what was at the start. 0.523moles of argon took up 0.723L(723mL) so 1.405 times as much gas would take 1.405 times as much space. so the volume would be ,

1.405*0.723=1.015L

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