using 0.5 m hci acid from a stock that is5m hci have to prepare 250 ml
To prepare 250 mL of a 0.5 M HCl acid solution from a stock solution that is 5 M HCl, you can use the formula:
C1V1 = C2V2
where:
C1 = concentration of the stock solution
V1 = volume of the stock solution
C2 = desired concentration of the diluted solution
V2 = desired volume of the diluted solution
In this case, the values are:
C1 = 5 M
V1 = ?
C2 = 0.5 M
V2 = 250 mL
To find the volume of the stock solution needed:
C1V1 = C2V2
(5 M)(V1) = (0.5 M)(250 mL)
Solving for V1:
V1 = (0.5 M)(250 mL) / 5 M
V1 = 25 mL
Therefore, you need to measure 25 mL of the 5 M HCl stock solution and dilute it with enough water or solvent to make a final volume of 250 mL.