Astock bottle of concentrated hydrochloric acid is a 37% (w/w) hcl solution. what is the molarity of this solution? how many moles of hcl are in a 10 ml sample of this concentrated acid? the density of 37% hcl is 1.19 g/ml.

Stock bottle weight to weight percentage is 37 %. This means that 1000 g of solution would contain 370 g of HCl.
therefore number of moles of HCl in 1000g - 370 g / 36.5 g/mol = 10.1 mol
the density of solution is 1.19 g/ml 
volume of 1 mL weighs - 1.19 g
then 10 mL would weigh - 11.9 g
so if 1000 g contains - 10.1 mol
then 11.9 g contains - 10.1 mol / 1000 g x 11.9 g = 0.120 mol 
therefore number of HCl moles in 10 mL is 0.120 mol

Answer) by studying proton collisions hope this : )