At 1.3 atm and 23 degrees Celsius, 12.5 grams of a gas occupies a volume of 8.2 liters. What is the molar mass (grams/mole) of the gas?

0.44 moles Molar Mass = 28.496

Explanation:

1.3(8.2)=n(0.0821)(23+273)

PV=nRT

12.5/0.43865

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