Hey, I am having a real hard time getting the answers to the problems. Any help would be greatly aprreciated!
1. When 11 mL of a solution containing 2.9 M AlBr3 is diluted to 33 mL, a dilute solution is formed. What is the Br- concentration in 25 mL of the dilute solution?
2. A stock solution is prepared by adding 23 mL of 1.2 M AlCl3 to enough water to make 76 mL. What is the Cl- concentration of 40 mL of the stock solution?
3. When 26 mL of a 335 mL stock solution containing 2.01 M Na2S is diluted to 76 mL, how many moles of Na+ are in the new solution?
4. When 48 mL of a solution containing 4.1 M AlCl3 is diluted to 50 mL, a dilute solution is formed. How many moles of Al3+ ions are contained in 14 mL of the dilute solution?
5. How many milliliters of a 135 mL solution of 1.7 M Na3PO4 must be used to make 71 mL of a solution that has a concentration of .6 M Na+?
6. A 11 mL sample of a solution of AlBr3 was diluted with water to 21 mL. A 17 mL sample of the dilute solution was found to contain 0.047 moles of Br-. What was the concentration of AlBr3 in the original undiluted solution?
One question per post, please. Show your work. Jiskha is here to help you learn, not to do your homework for you.
I'd be happy to help you with these problems! In order to solve these problems, you'll need to use the concept of dilution and apply the formula:
C1V1 = C2V2
Where:
C1 = initial concentration of the stock solution
V1 = initial volume of the stock solution
C2 = final concentration after dilution
V2 = final volume after dilution
Let's go through each problem step by step:
1. When 11 mL of a solution containing 2.9 M AlBr3 is diluted to 33 mL, a dilute solution is formed. What is the Br- concentration in 25 mL of the dilute solution?
To solve this problem:
- Use the formula C1V1 = C2V2
- C1 = 2.9 M (initial concentration)
- V1 = 11 mL (initial volume)
- C2 = ? (final concentration)
- V2 = 33 mL (final volume)
Now you can solve for C2:
C2 = (C1V1) / V2 = (2.9 M * 11 mL) / 33 mL = 0.9667 M
So, the Br- concentration in 25 mL of the dilute solution is 0.9667 M.