A concentrated HCl solution is described in the bottle as containing 36%(mass by volume) of HCl.what is the molar concentration of this volume?

1 Answer
Jan 11, 2018

You need the density of the solution. If the density is #1.18# #g"/"cm^3#, the molarity is about #12# #mol"/"L#.

Explanation:

Suppose the density of the concentrated #HCl# solution is #1.18# #g"/"cm^3#.
https://wissen.science-and-fun.de/chemistry/chemistry/density-tables/density-of-hydrochloric-acid/

Then, take #1# L of the solution.
Its mass is #1000(cm^3) * 1.18 (g"/"cm^3)=1180# g, and it contains #1180 (g) * 36/100 = 425 (g)# of hydrochloric acid.

The molar mass of #HCl# is #36.5 (g"/"mol)#. #1# L of the concentrated solution contains #(425(g)) /(36.5 (g"/"mol))=11.64…~=12# moles of #HCl#.