Sciencemadness Discussion Board

molarity questions

nodrog19 - 15-6-2008 at 19:49

"distillation gives an azeotrope with a concentration of 68% HNO3 and a boiling temperature of 120.5 °C."

What molarity is this?
Does is mean 68 mol HNO3 +32mol H2O?


Also, if all the Sulfuric acid is removed from 57.7ml of 17.311 molar (93.2%), should 6.8% volume of water be left?

[Edited on 15-6-2008 by nodrog19]

Magpie - 15-6-2008 at 21:02

Molarity is moles/liter. The % is weight % for both acids.

To calculate molarity for the nitric you need its density. For 68% nitric my handbook says density = 1.40.

So the weight of a liter is 1400g, and the weight of HNO3/liter is = (0.68)(1400g) = 968g

MW = 63.01

Molarity = 968g/(63.01g/mole) = 15.4

Same kind of routine for the sulfuric acid.

[Edited on 15-6-2008 by Magpie]

nodrog19 - 16-6-2008 at 08:30

Thank you very much
What is the density for 60% HNO3?

[Edited on 16-6-2008 by nodrog19]

nodrog19 - 16-6-2008 at 08:42

never mind, its 1.367
molarity=13.02

[Edited on 16-6-2008 by nodrog19]