The temperature of air in a foundry increases when molten metals cool and solidify. Suppose 9,900,000 J of energy is added to the surrounding air by the solidifying metal. The air’s temperature increases by 5 C, and the air has a specific heat capacity of 1,000 J/g*C. What is the mass of the heated air?

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 :