When 50mL of 2M solution of N2O5 was heated ,.28L of O2 at NTP was formed after 30 minutes. Calculate the concentration of unreacted N2O5 at that time and also find the average rate of reaction.

 

I want to know the method of doing it.

 

Here, my friend. do it as follows :-

 

1.      Reaction is   :    2N₂0₅   ->  4NO₂ + O₂

2.      Now, at STP, 1 mole of gas occupies 22.4 litres.

3.      So, 28 litres of oxygen are occupied by 1.25 moles of O₂.

4.      Now, you have provided the molarity as well as the volume 

         of  N₂0₅ present at the starting through which you can calculate the

         initial amount of moles present.

5.      Also, 2 moles of N2O5 gives 1 mole of oxygen.

        So, 1.25 moles of oxygen is given by 2.5 moles of N2O5.

6.     So, now you get the amount of N2O5 left

7.     As far as rate is concerned, it is  = -- ( Amount of N2O5 used ) / time