Which one has a greater concentration, 1 molar NaOH or 1 molal NaOH aqueous solution?

[xec]

Which one has a greater concentration, 1 molar NaOH or 1 molal NaOH aqueous solution?
for the answer Explain Why!

[symbolipoint]

The question needs some clarity. Do you need emphasis on moles or on mass of the solute? Once you establish this, next you must make reference based on comparable concentration units.

[Borek]

Calculate molality of 1M NaOH and molarity of 1m NaOH, everything should be clear then.

Note that you will need solution density for conversion. This has to be taken from density tables.

Symbolipoint is right in general, but wrong in this particular case :wink: Besides, looks to me like in practice it always works the same.

Borek
--
concentration lectures (http://www.chembuddy.com/?left=concentration&right=toc) & concentration conversion (www.chembuddy.com/?left=CASC&right=concentration_conversion)

[symbolipoint]

I forgot to account properly for the fact that the same solute (NaOH) is used in both liquids.

Borek commented:
Symbolipoint is right in general, but wrong in this particular case Besides, looks to me like in practice it always works the same.