Commercial bleach contains 5.25% (by mass) of NaClO in water. It has a density of 1.08 g/mL. Calculate the molarity of this solution. (Hints: assume you have 1 L of solution (mass 1080 g); molar mass of NaClO is 74.4 g/mol)

How much does a L weight?

1000 mL x 1.08 g/mL = 1080 grams.
How much of that is NaClO?
1080 g x 0.0525 = ?? grams NaClO.
How many moles NaClO is that?
??grams NaClO/molar mass NaClO = moles NaClO and that is in 1 L of solution so that is the molarity.

To calculate the molarity of a solution, we need to know the number of moles of the solute (NaClO) and the volume of the solution.

First, let's calculate the number of moles of NaClO in the solution. We can do this by using the mass percent and the molar mass of NaClO.

Step 1: Calculate the mass of NaClO in the solution
Given that the mass percent of NaClO is 5.25% and the mass of the solution is 1080 g, we can calculate the mass of NaClO as follows:

Mass of NaClO = Mass percent × Mass of solution
Mass of NaClO = 5.25% × 1080 g
Mass of NaClO = (5.25/100) × 1080 g
Mass of NaClO = 56.7 g

Step 2: Calculate the moles of NaClO
Now that we have the mass of NaClO, we can calculate the number of moles using its molar mass:

Number of moles of NaClO = Mass of NaClO / Molar mass of NaClO
Number of moles of NaClO = 56.7 g / 74.4 g/mol
Number of moles of NaClO ≈ 0.763 moles

Next, let's calculate the volume of the solution in liters.

Given that the mass of the solution is 1080 g and the density of the solution is 1.08 g/mL, we can calculate the volume as follows:

Volume of solution = Mass of solution / Density of solution
Volume of solution = 1080 g / 1.08 g/mL
Volume of solution = 1000 mL / 1.08 g/mL (since 1 L = 1000 mL)
Volume of solution ≈ 925.93 mL ≈ 0.92593 L

Now we can calculate the molarity of the solution:

Molarity = Number of moles of solute / Volume of solution (in L)
Molarity = 0.763 moles / 0.92593 L
Molarity ≈ 0.825 M

Therefore, the molarity of the solution is approximately 0.825 M.

To calculate the molarity of the solution, we need to determine the number of moles of NaClO present in the solution.

First, let's calculate the mass of NaClO in 1 L of solution.

The density of the solution is given as 1.08 g/mL. Therefore, the mass of 1 L (1000 mL) of solution can be calculated as:

Mass of solution = density × volume
Mass of solution = 1.08 g/mL × 1000 mL = 1080 g

Since the bleach concentration is given as 5.25% (by mass) NaClO, we can calculate the mass of NaClO present in 1080 g of the solution:

Mass of NaClO = 5.25% × 1080 g = 56.7 g

Now, let's convert the mass of NaClO to moles:

Number of moles of NaClO = Mass of NaClO / Molar mass of NaClO
Number of moles of NaClO = 56.7 g / 74.4 g/mol = 0.762 moles

Finally, we calculate the molarity using the equation:

Molarity (M) = Number of moles / Volume (L)

Since we have 1 L of solution, the molarity is simply equal to the number of moles:

Molarity of the solution = 0.762 moles/L