Question

Calculate the molarity of naoh solution when solution when 20g naoh dissolved in 250ml water?

Answer 1

Answer:

Molarity = 2 M

Explanation:

Given

mass of NaOH = 20 g

volume = 250 ml⇒ 0.25 L

Molarity = ??

Solution

Molarity = moles / volume in liters

moles of NaOH = 20 / 40

moles of NaOH = 0.5 moles

putting values

Molarity = 0.5 / 0.25

Molarity = 2 M

Answer 2

Answer:

2 M

Explanation:

We have :

Given mass = 20 g

Volume = 250 mL

We know :

Molar mass of NaOH = ( 23 + 16 + 1 ) = 40 g / mol

Now :

No. of moles = 20 / 40 moles

No. of moles = 0.5 moles

Molarity = ( No. of moles of solute / Volume of solution in lite )

Molarity = ( No. of moles of solute / Volume of solution in mL ) × 1000

Molarity = ( 0.5 / 250 ) × 1000 M

= > Molarity = 0.5 × 4 M

= > Molarity = 2 M

Therefore , we get required answer.