Question

please show work

so: 1 ml stock 10 ml final -0.5 mL of stock -5 ml final volume While I have used 1:10 as a standard the same rules apply for all dilution factors. Try these problems: x 0.5 X0.5 1. You need to make a 1:25 dilution factor. If you final volume is 25 mL this means that you need_ _mL of stock and mL of solvent to make your final volume of 25 mL. 2. If you needed to make 200 mL of the same solution at 1:25, it would mean that you need mL of stock and _mL of solvent. 3. If you needed to make a 1:50 dilution of a solution, how many mL of stock and solvent would you need to make a total of 1000 mL? 4. The molecular weight of the molecule KCl is 74.5. Now calculate how many grams you need to weight out in order to make a 2.4 M solution of KCI. Show all work: How much water do you need to add? What if you only wanted a total of 100 ml of a 2.4 M solution of KCI? How many grams of KCl would you need just for 100 ml? Assume you made a 2.4 M solution of KCl. Then you needed a solution that was 10 times more dilute (a 1:10 dilution of the original) than this. If you took 1 ml of the 1.5 M solution, how much water would you add to get to a total of 10 ml? If you took 10 ml of the 2.4 M KCl solution, how much water would you add to get a 1:10 dilution?

Answer 1

Question 1 Using Veste Va So where V1 = volume of stock. v2 = volume of final solution Si= concentration of stock , sqz final concen we need to make a 1.25 délution factor ie. Sy is 25 times than sa. 2. S1 = 2552 final volume Ug = 25 ml Son Vis1 = V2 S2 St 2500 255g Ve. (25 Sq) = (25 ml). Sa Va = 1 me So, we need 1 mL stock solution and (25 mL-1mL) = 24 mL of solvent to make final volume of 25 mL. 2. This time the dilution factor is same but total volume is 200mh which is 8 times of go wels, so we can multiply the required volumes in the last calculation by

We need to add 100omh water since Kel is solid. If we wanted only 100 mh solution of kel, we will require 178.8 g = 17.88 g kee 20 10

E To make a 1: 10 dilection of Imt 1.5 solution to 10mh, we need to add 9 mL water. So from Ve Sa = V2 S2 Using the same rule, to make a 1.10 dilution of 10mL 2.4M Kee, the total volume should be 100 ml which means we need 9omt water,