Question

show a complete calculation of the concentration of your diluted solution prepared by diluting 20 ml of stock solution to a final volume of 25 ml including prpagation uncertainty . CuBr2 being our stock solution with the (0.4008g of sample of Cubr2)in 50ml )

Answer 1

Molarity of stock solution , M = ( Mass/molar mass) x ( 1000 / Volume in mL)

= ( 0.4008 g / 223.4(g/mol)) x ( 1000 / 50 mL)

= 0.0359 M

According to law of dilution   MV = M'V'

Where M = Molarity of stock = 0.0359 M

V = Volume of the stock = 20 mL

M' = Molarity of dilute solution = ?

V' = Volume of the dilute solution = 25 mL

Plug the values we get   , M' = (MV) /V'

= (0.0359x20)/25

= 0.0287 M

Therefore the concentration of the dilute solution is 0.0287 M