determine the volume of stock acid required to prepare 500mL of 0.5mol/L hydrochloric acid. Assume the stock acid is 38% by mass hydrogen chloride and has a density of 1190kg/m3 (1.190g/mL)
assume one liter of stock.
mass stock= 1190g
mass HCL= 1138*.38=432g
moles HCL= 432/37=11.7
Molarity=1.17/1=1.17
so you want to dilute it 11.7/.5=23.4times
so you need one part stock, 22.4 parts water.
each part= 500ml/23.4=21.4ml
21.4ml stock
479 ml H2O
check me.