Question

50 mL 3.0 M HCl(aq) that means hw much HCl . Can anybody ilaborate it

Answer 1

0.050 Liter x 3.0 mole/Liter = 0.150 moles of HCl

Each mole of HCl contains 36.5 g, so that aqueous sample contains 5.48 g of HCl.

For a review, see
http://dl.clackamas.cc.or.us/ch105-04/molarity.htm