Question

Concentrated nitric acid used in labortary as 68%nitric acid by mass in aqueous solution.what should be the molarityof such a sample of the acid if the density of solution is 1.504gm

Answer 1

68% by mass means 68 gm of HNO3 is dissolved in 100 g of water.

So moles = wt. Of HNO3 / Molecular mass of HNO3

= 68/63

= 1.07

As density of solution is 1.504 gm/mL

So V = m/d = 100/1.504 = 66.48 mL

As we know Molarity = Moles/volume in L

= 1.07/68/1000

= 15.73 M