Question

A 90.0 g sample of NaOH is dissolved in water and the solution is diluted to give a final volume of 3.00 liters. The molarity of the final solution is

Answer 1

First convert grams to moles:
90.0g *(mole/39.997) = 2.250mole
Remember that molarity is moles per liters:
2.250mol/3L = .750 M

Answer 2

Answer:

0.750 M

Explanation:

Mass of NaOH $= 39.97 gm$

Number of moles in 90 gm of NaOH

$= 90 gm (\frac{Number of moles }{39.97})\\ = 2.250 mole\\Molarity = \frac{number of moles}{Volume of solution} \\= \frac{2.25}{3.00} \\= 0.750 Moles /litre$