In order to make a #1*mol*L^-1# solution of #NaNO_2# in water, how many grams of sodium nitrite are necessary?

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1 Answer
Jan 21, 2016

Concentration #=# #("moles")/("volume of solution")#. Here you need a #1# #mol*L^-1# solution.

Explanation:

We require, #(5*mmol)/(5*mL)# #=# #(5xx10^(-3)*mol)/(5xx10^-3*L)# #=# #1# #mol# #L^-1#

Note that the #m# prefix simply means #xx10^-3#. So #mmol*mL^-1# is precisely #1# #mol*L^-1#.

So to make this volume we simply take a #5# #mL# volume of #1# #mol*L^-1# sodium nitrite.

It would be best to make a stock solution. Accurately weigh #70.00# #g# of sodium nitrite, and quantitatively transfer this to a #1# #L# volumetric flask. Fill up to the mark with distilled water, and make sure all the solid is dissolved.