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Chemistry Forums for Students => Undergraduate General Chemistry Forum => Topic started by: mana on February 05, 2016, 10:00:53 AM

Title: calculation the concentration of NaOH (gr) in 250 ml, 0.1 M solution
Post by: mana on February 05, 2016, 10:00:53 AM

hi all
I want to prepare a solution of NaOH in my book, it has mentioned for a 0.1 M solution of 250 ml sodium hydroxide solution, I should use 1.11 gr NaOH, the calculation is as below, I can understand all of the calculation except the final part, pls take a look and help me :'(

? gr NaOH=250ml (solution)* (0.1 mol NaOH/1000ml solution )* (40gr NaOH/ 1mol NaOH)* (100 g solution/90gr NaOH)=1.11 gr NaOH

I can't understand why do I need to multiple at  (100 g solution/90gr NaOH)?

Title: Re: calculation the concentration of NaOH (gr) in 250 ml, 0.1 M solution
Post by: AWK on February 05, 2016, 12:23:54 PM

Seems to be 90 % NaOH, not a pure one.

Title: Re: calculation the concentration of NaOH (gr) in 250 ml, 0.1 M solution
Post by: mana on February 05, 2016, 02:58:06 PM

Quote from: AWK on February 05, 2016, 12:23:54 PM

Seems to be 90 % NaOH, not a pure one.

THANKS