posted by Cassandra
Hi, can you help with how to solve this equation?
50.0 gram sample of NaCl is added to water to create a 0.50 L solution. What volume of this solution is needed to create a 1.30 L solution that is 0.100 M NaCl?
The choices provided:
a) 152 mL
b) 255 mL
c) 87.6 mL
d) 412 mL
I tried various ways to solve using Molarity and converting the grams of NaCl to moles. No answer comes close. Thank you, Cass
mols NaCl = 50/molar mass = ?M which is approx 0.9 but you need a more accurate answer than that for this as well as the other calculations.
M of the NaCl solution is about 0.9/0.5 = about 1.8 M. Then
mL1 x M1 = mL2 x M2
mL1 x 1.8 = 1300 x 0.1M
You're right. Remember the 1.8 is approx. No choice is close. Key must be wrong. What's the 10.1 mL. Is that the e choice.
Thanks for replying. Sorry, the 10.1 is the (e) choice. I had tried various ways after I posted my question and I may have found the answer. I used the Dilution equation and found an answer of .152 L which would then convert to (a) of 152 mL. Still not sure if it is correct and will take what you provided. Thanks again. Cass
If you will post how you obtained the 152 mL I shall be happy to check it for you.