A. 50 g of nitrogen (n2) has a volume of liters at stp.

39.98 liters

Explanation:

The first you should know:  At STP , 1 mole of any  gas takes up 22.4 Liters of volume.

After, you will find the molecular weight (MW) of N2 with help of a periodic table.

Then N= 14,007 g      

So:  

N2 = 14,007 * 2      

MW =28,014 g/ mol N2  

Now you will start with the data of 50 grams of N2 and you obtain:    

50 g N2  x 1 mol N2    x  22.4 L N2      =  39.98 L at STP                                 28,014 g N2        1 mol N2      

b.final

the dissolution of polymer can be thermodynamically described in 2 steps.