calculate the molarity of a solution prepared by dissolving 5g of sodium hydroxide in water to make 1l of solution
moles NaOH = grams/molar mass
M = moles/L soln.
To calculate the molarity of a solution, you need to know the number of moles of solute (in this case, sodium hydroxide) and the volume of the solution in liters.
Step 1: Convert the mass of sodium hydroxide into moles.
The molar mass of sodium hydroxide (NaOH) is:
Na = 22.99 g/mol
O = 16.00 g/mol
H = 1.01 g/mol
So, the molar mass of NaOH is:
22.99 + 16.00 + 1.01 = 39.00 g/mol
To find the number of moles, divide the mass of sodium hydroxide (5g) by the molar mass (39.00 g/mol):
5g ÷ 39.00 g/mol = 0.1282 mol
Step 2: Calculate the molarity.
Molarity (M) is defined as moles of solute divided by liters of solution. In this case, you have 0.1282 moles of sodium hydroxide and 1 liter of solution.
Molarity (M) = moles of solute / volume of solution (in liters)
M = 0.1282 mol / 1 L = 0.1282 M
So, the molarity of the solution is 0.1282 M.