How do I prepare a "3 M" "NaOH" aqueous solution?

1 Answer
Truong-Son N.
Aug 21, 2015

It depends on how accurate you want it. If you just want "3.000 M", and you want to be practical:

"NaOH: 39.9959 g/mol"

Using a "100.00-mL" volumetric flask gives you two decimal places of accuracy and is not that wasteful.

cancel("100.00 mL") * ((3.000 cancel("mol"))/(cancel("1000" "mL")))("39.9959 g"/(1 cancel("mol")))

= "11.9988 g" -> "12.00 g" to four sig figs.

which is a reasonable amount to measure out in lab. If you want to use "12.00 g" because it's easier, that gives you:

("12.00 g"/"39.9959 g/mol")/(100.00 cancel"mL" xx "1 L"/(1000 cancel"mL")) = "3.000 M"

(So you don't even need a scale that measures out to 4 decimal places.)

Related questions
Impact of this question
3282 views around the world
You can reuse this answer
Creative Commons License