You have 100.0 mL of 0.2500 M solution of NaCl sitting in a beaker. After several days you test the solution and find out that it is now 0.3721M. How much water must have evaporated??
I got 67.2 mL but its the wrong answer.. PLS HELP!
use mmoles as mmoles at end mus be same as at start.
100.0 ml x 0.2500 M = (final vol) x 0.3721 M
so final volume =
100.0 ml x 0.2500 M/0.3721 M
I got 53.75 ml as the final volume.
hence you can calculate how much water has evaporated.
Thank you for your help :) but the correct answer according to my prof was 32.8mL i am not even sure if C is the correct answer or a typo.
I was give 5 options to choose from:
a) concentration can not change because of evaporation
b) 100.0 mL
c) 32.8 mL
d) 67.2 mL
e) 12.2 mL
oops
Sorry a typed 100.0 ml x 0.2500 M/0.3721 M but put 0.2000 into my calculator!!
I got 67.186 ml as the final volume.
Yes, so C
what is 4.00g KCI in 40.0mL of solution. give answer to two significant forms
EX予約
Well, if you have a 0.2500 M solution turning into a 0.3721 M solution, it seems like your water molecules have been a bit mischievous and decided to go on vacation. But don't worry, we'll figure out how much of them went missing!
To solve this, we can use the dilution formula: C₁V₁ = C₂V₂, where C₁ is the initial concentration, V₁ is the initial volume, C₂ is the final concentration, and V₂ is the final volume.
Initially, you have 100.0 mL of your 0.2500 M solution, so C₁ = 0.2500 M and V₁ = 100.0 mL.
After some time, the solution becomes 0.3721 M, so C₂ = 0.3721 M.
Now, let's solve for V₂ (the final volume), which is the total volume after some evaporation has occurred.
(0.2500 M) * (100.0 mL) = (0.3721 M) * (V₂)
By rearranging the equation, we can find V₂:
V₂ = (0.2500 M * 100.0 mL) / 0.3721 M
Calculating this, we find V₂ ≈ 67.2725 mL.
So, it seems like approximately 67.2725 mL of the water in your solution decided to make a getaway. It looks like you were close with your answer of 67.2 mL, just a little bit off! Keep up the good work, and don't worry, those water molecules will come back... maybe with a postcard!
To determine the amount of water that evaporated, we can use the concept of dilution. Initially, we had a 0.2500 M solution of NaCl with a volume of 100.0 mL. After evaporation, the concentration increased to 0.3721 M.
To solve this problem, we can use the equation:
M1V1 = M2V2
Where:
M1 = initial concentration of the solution (0.2500 M)
V1 = initial volume of the solution (100.0 mL)
M2 = final concentration of the solution (0.3721 M)
V2 = final volume of the solution (unknown)
Rearranging the equation, we have:
V2 = (M1V1) / M2
Plugging in the given values, we get:
V2 = (0.2500 M) * (100.0 mL) / (0.3721 M)
V2 ≈ 67.37 mL
So, according to my calculations, approximately 67.37 mL of water must have evaporated from the initial solution. Double-check your calculations to ensure accuracy.