The cost of table NaCl is Rs.20 per kg. Calculate its cost permole.

Rs. 1.2 per mole

Explanation:

Given parameters:

 Cost of NaCl = Rs. 20 per kg

Unknown:

Cost per mole  = ?

Solution:

The problem here is simply to convert the unit to:

      Rs. per mole

        Number of moles  =  

 Molar mass of NaCl  = 23 + 35.5  = 58.5g/mol

 Now, for 1kg;

            Number of moles  =   = 17.1moles  

So;

             x   = Rs. 1.2 per mole

58750.08068 is the answer i think