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

0.750 M

Step-by-step explanation:

Mass of NaOH
`= 39.97 gm\\`

Number of moles in 90 gm of NaOH

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