Kitty F.

asked • 12/05/14

Mass of NaOH needed to make 500mL of 0.1M NaOH solution?

I'm working on a solutions lab and would like someone to look over my calculations please.
 
The question asked:
"What mass of solid NaOH is needed to make 500mL of 0.1M NaOH solution?"
 
My work:
Needed:  500mL solution with a final concentration of .1M
 
Na:  22.989 amu
O:   15.999 amu
H:   1.008 amu
=39.996 amu  (rounded to 40amu)
40 amu= 1 mole NaOH
 
To make one mole NaOH solution, dissolve 40 grams NaOH in 500mL of H2O.
 
mL to L conversion:
500/1000=.5
For .5L of 0.1M solution, we need 0.1M of solute.
0.1M of solute x 40 grams/Mole= 4 grams NaOH
 
The solution would be made by dissolving 4 grams NaOH in .5 Liters of H2O

2 Answers By Expert Tutors

By:

Siddharth B. answered • 03/29/20

Tutor
New to Wyzant

John G. answered • 12/05/14

Tutor
4.8 (52)

Understanding math via the real world.

Ayilumo J.

I think the answer should be 2 g not 4g
Report

11/15/15

Still looking for help? Get the right answer, fast.

Ask a question for free

Get a free answer to a quick problem.
Most questions answered within 4 hours.

OR

Find an Online Tutor Now

Choose an expert and meet online. No packages or subscriptions, pay only for the time you need.