Question

Calculate the mass of NaOH needed to no
a solution with final mass 60g. The density
is 1.5g/cm². The molarity of solution = 2.20​

Answer 1

final mass=60g

density=1.5g/cm³

volume=mass/density

=60/1.5

=40cm³

therefore,

volume of solution= 40cm³= 40mL (1cm³=1mL)

molarity=2.20

molarity=moles of solute/volume of solution in L

=moles of solute*1000/volume of solution in mL

2.20=moles of solute*1000/40

moles of solute=(2.20*40)/1000

=0.088

solute=NaOH

molar mass of NaOH=40g

moles of solute=given gram mass/molar mass

0.088=given gram mass/40

given gram mass =0.088*40

=3.520g

therefore mass of NaOH needed=3.520g