2) Three naturally occurring isotopes exist for the hypothetical element X -isotope #1 has an abundance of 12% a mass number of 23 and 14 neutrons
-isotope #2 has an abundance of 21% and 6 neutrons
-isotope #3 has 10 neutrons
What is the atomic mass of this element? (10 points)

answer: the value of enthalpy change will be -152.80 kj.

solution:

pressure = 1atm , temperature = = 298 k

given that pressure and temperature are same in both gases , the number of moles of both gases can be determined by the ideal gas equation.

according to reaction 3 moles no are reacting with 1 mol of ,then 0.49 mol of no will react with moles of ozone that is 0.16 moles of ozone. since, no is limiting reagent and is an excessive reagent.

enthalpy change for the reaction between the given volumes of the gases is :