Calculate the molarity of a solution prepared by dissolving 25.0 g NaCl in 1.0 L solution.
moles = grams/molar mass
M = moles/L solution.
To calculate the molarity of a solution, you need to know the amount of solute (in moles) and the volume of the solution (in liters). First, you need to convert the mass of NaCl into moles using its molar mass. The molar mass of NaCl is the sum of the atomic masses of sodium (22.99 g/mol) and chlorine (35.45 g/mol), which totals to 58.44 g/mol.
To convert grams to moles, divide the mass of NaCl (25.0 g) by its molar mass (58.44 g/mol):
25.0 g NaCl / 58.44 g/mol = 0.428 mol NaCl
Now that we know the moles of NaCl, we divide it by the volume of the solution (1.0 L) to find the molarity:
Molarity (M) = Moles of solute (mol) / Volume of solution (L)
M = 0.428 mol NaCl / 1.0 L = 0.428 M
Therefore, the molarity of the NaCl solution prepared by dissolving 25.0 g of NaCl in 1.0 L of solution is 0.428 M.