determine the molarity of each of the following solutions:
a. 20.0 g NaOH in enough H2O to make 2.00 L of solution
is the answer .250 M
yes
To determine the molarity (M) of a solution, we need to calculate the number of moles of solute (in this case, NaOH) present in the given volume of solution.
First, we need to calculate the number of moles of NaOH:
1. Determine the molar mass of NaOH. The atomic mass of Na is 22.99 g/mol, the atomic mass of O is 16.00 g/mol, and the atomic mass of H is 1.01 g/mol.
So, the molar mass of NaOH = (22.99 g/mol) + (16.00 g/mol) + (1.01 g/mol) = 39.00 g/mol.
2. Convert the given mass of NaOH (20.0 g) to moles:
Number of moles = given mass / molar mass
Number of moles = 20.0 g / 39.00 g/mol ≈ 0.513 mol.
Next, we need to determine the volume of the solution in liters (L):
The volume of the solution is given as 2.00 L.
Finally, we can calculate the molarity (M) of the solution:
Molarity = moles of solute / volume of solution in liters
Molarity = 0.513 mol / 2.00 L = 0.2565 M ≈ 0.256 M (rounded to three significant figures)
Therefore, the molarity of the NaOH solution is 0.256 M or approximately 0.256 M.