You have a sample which consists of 428g sodium hydroxide (NaOH)
dissolved in enough water to make a final solution of 6.4l. What is the
molarity?
First, we need to calculate the number of moles of sodium hydroxide present in the solution:
moles of NaOH = mass of NaOH / molar mass of NaOH
moles of NaOH = 428g / 40.00g/mol (molar mass of NaOH)
moles of NaOH = 10.70 mol
Next, we need to calculate the molarity:
molarity = moles of solute / volume of solution
molarity = 10.70 mol / 6.4 L
molarity = 1.67 M
Therefore, the molarity of the sodium hydroxide solution is 1.67 M.
To find the molarity of the solution, we need to calculate the number of moles of sodium hydroxide (NaOH) present and then divide it by the volume of the solution.
The molarity (M) is defined as moles of solute per liter of solution.
Given:
Mass of NaOH = 428 g
Volume of solution = 6.4 L
Step 1: Convert the mass of NaOH to moles.
The molar mass of NaOH (sodium hydroxide) is:
Na = 23.0 g/mol
O = 16.0 g/mol
H = 1.0 g/mol
So, the total molar mass of NaOH is 23.0 + 16.0 + 1.0 = 40.0 g/mol.
To find the number of moles, divide the mass by the molar mass:
Number of moles = mass / molar mass
Number of moles of NaOH = 428 g / 40.0 g/mol = 10.7 mol
Step 2: Calculate the molarity.
Molarity (M) = moles of NaOH / volume of solution (in liters)
Molarity = 10.7 mol / 6.4 L = 1.67 M
Therefore, the molarity of the solution is 1.67 M.