If the decomposition of a sample of KClO3 produces 3.29 g of O2. What was the mass (g) of the original sample?

8.41 g

Explanation:

To calculate the moles :

The balanced chemical equation for decomposition is :

According to stoichiometry :

As 3 moles of are produced by = 2 moles of

Thus 0.103 moles of are produced by =  of

Mass of

8.41 g was the mass of the original sample.

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 :