The correct option is D 0.21 M
2%(w/v) solution means 2 g of NaOH is present in 100 mL of the solution.
Number of moles of NaOH=given mass of NaOHmolar mass
=240=0.05
Molarity=number of moles of solutevolume of solution in mL×1000
Molarity=0.05100×1000=0.5 M
Conserving moles before and after dilution:
M1V1=M2V2
Where, M1=0.5 M and V1=250 mL
M2 and V2 are the molarity and volume of the resultant solution.
(0.5×250)=(M×600)
M=0.21 M
Molarity of the resultant solution is 0.21 M.