How many grams of naoh are needed to prepare 250ml of 0.205 m naoh?

Concentration

=

Moles of solute (moles)

Volume of solution (L)

Thus

Concentration

*

volume

=

moles of solute

0.205

⋅

m

o

l

⋅

L

-

1

*

0.250

⋅

L

=

Moles of solute

=

0.0513

⋅

m

o

l

, an answer in moles as required.

And thus

mass of NaOH

=

moles

*

molar mass

=

0.0513

⋅

m

o

l

*

40.0

⋅

g

⋅

m

o

l

-

1

=

2.05

⋅

g