250ml solutions is prepared on dissolving 20g NaOH. Calculate the molarity of solution
how many moles NaOH?
how many liters of solution?
M = moles/liter
To calculate the molarity of a solution, you need to use the formula:
Molarity (M) = moles of solute / volume of solution in liters
First, let's calculate the moles of NaOH.
The molar mass of NaOH is:
Na (Sodium) = 22.99 g/mol
O (Oxygen) = 16.00 g/mol
H (Hydrogen) = 1.01 g/mol
So, the molar mass of NaOH is:
22.99 g/mol + 16.00 g/mol + 1.01 g/mol = 39.99 g/mol
Now, let's calculate the moles of NaOH:
moles = mass / molar mass = 20 g / 39.99 g/mol ≈ 0.500 mol
Now, let's calculate the volume of the solution in liters. We have 250 mL, but it needs to be converted to liters:
volume = 250 mL / 1000 mL/L = 0.250 L
Finally, let's calculate the molarity:
Molarity = moles / volume = 0.500 mol / 0.250 L = 2.000 M
Therefore, the molarity of the NaOH solution is 2.000 M.