what does it mean when we say that concentrated nitric acid has 16 molars

Answer 1

I've not heard the expression you list but I've heard something close to that. I've heard that concd HNO3 is 16 molar (written as 16M). What that means is that there are 16 moles of HNO3 in a liter of the solution. Since 1 mole HNO3 is 63 grams, 16 moles would be 16 x 63 = 1.008 kg/liter of the soln.