Question

A sample of concentrated nitric acid has a density of 1.41gmL and contains 70.0% HNO3 by mass. (a).what mass of HNO3 per liter of solution? (b).what is the molarity of the solution

Answer 1

Well, we need to make the calculation...`"moles of solute"/"volume of solution"`

Explanation:

And we are given that `rho_"acid"=1.41*g*mL^-1`..

.............and so ...........

`"mass of a litre volume"-=1.41*g*mL^-1xx1000*mL*L^-1=1410*g`

And we can work out the concentration of the nitric acid solution, simply by taking a `1*mL` volume....

`[HNO_3(aq)]="moles of acid"/"volume of solution"=`

`((1.41*gxx70.0%)/(63.01*g*mol^-1))/(1*mLxx10^-3*L*mL^-1)=15.7*mol*L^-1`

...`68-70%w/w` is the concentration that we typically use in the lab.