Final answer:
To find the molarity of the NaCl solution, divide the moles of NaCl by the volume of the solution in liters. In this case, the molarity is 0.696 M.
Step-by-step explanation:
The molarity of a solution is calculated by dividing the moles of solute by the volume of the solution in liters. To find the moles of solute, we need to convert the given mass of NaCl to moles using its molar mass. The molar mass of NaCl is 58.44 g/mol.
Given that 5.09 grams of NaCl is dissolved in water, we can use the formula:
Molarity (M) = moles of solute / volume of solution (L)
First, we need to convert the mass of NaCl to moles:
moles of NaCl = 5.09 g / 58.44 g/mol = 0.087 moles
Next, we need to convert the volume of the solution to liters:
Volume of solution = 125.0 mL = 0.125 L
Now we can calculate the molarity:
Molarity (M) = 0.087 moles / 0.125 L = 0.696 M