Household bleach is an aqueous solution that contains 5.25g of sodium chlorite, NaOCl (aq), per 100.0mL of solution. What is the molar concentration of sodium hypochlorite in bleach?
5.25 g/100 mL solution = 52.5 g/1000 mL solution.
mols NaOCl in 52.5 g = mols/molar mass = 52.5/74.5 = 0.705 mols/L = 0.705 M By the way, NaOCl is sodium HYPOchlorite. Sodium chlorite is NaClO2.
To find the molar concentration of sodium hypochlorite (NaOCl) in bleach, we need to calculate the number of moles of NaOCl in 100.0 mL of the solution.
First, we need to convert the mass of NaOCl in grams to moles. The molar mass of NaOCl is the sum of the atomic masses of sodium (Na), oxygen (O), and chlorine (Cl):
Molar mass of NaOCl = Atomic mass of Na + Atomic mass of O + Atomic mass of Cl
The atomic masses are as follows:
Na: 22.99 g/mol
O: 16.00 g/mol
Cl: 35.45 g/mol
Molar mass of NaOCl = 22.99 g/mol + 16.00 g/mol + 35.45 g/mol = 74.44 g/mol
Now we can calculate the number of moles using the formula:
Number of moles = Mass (g) / Molar mass (g/mol)
Mass of NaOCl = 5.25 g
Number of moles = 5.25 g / 74.44 g/mol = 0.0704 mol
The molar concentration is the number of moles divided by the volume in liters.
Volume of solution = 100.0 mL
Convert mL to L: 100.0 mL * (1 L / 1000 mL) = 0.100 L
Molar concentration = Number of moles / Volume (L)
Molar concentration = 0.0704 mol / 0.100 L = 0.704 mol/L
Therefore, the molar concentration of sodium hypochlorite in bleach is 0.704 mol/L.
To determine the molar concentration of sodium hypochlorite (NaOCl) in bleach, we need to convert the given mass of NaOCl to moles and then divide it by the volume of the solution in liters.
First, let's convert the given volume of solution from milliliters (mL) to liters (L):
Volume of solution = 100.0 mL = 100.0 mL * (1 L / 1000 mL) = 0.100 L
Next, we need to convert the mass of NaOCl to moles using the molar mass of NaOCl, which is the sum of the atomic masses of sodium (Na), oxygen (O), and chlorine (Cl). The atomic masses can be found on the periodic table:
Na: 22.99 g/mol
O: 16.00 g/mol
Cl: 35.45 g/mol
Molar mass of NaOCl = 22.99 g/mol + 16.00 g/mol + 35.45 g/mol = 74.44 g/mol
Now, we can calculate the moles of NaOCl in the given mass:
Moles of NaOCl = 5.25 g / 74.44 g/mol
Finally, we can calculate the molar concentration (also known as molarity or c) by dividing the moles by the volume:
Molar concentration of NaOCl = Moles of NaOCl / Volume of solution
So, simply divide the moles of NaOCl obtained earlier by the volume of the solution:
Molar concentration of NaOCl = (5.25 g / 74.44 g/mol) / 0.100 L
Calculate the expression in the parentheses first:
Molar concentration of NaOCl = 0.0705 mol / 0.100 L
Finally, divide the moles (mol) by liters (L) to get the molar concentration:
Molar concentration of NaOCl = 0.705 mol/L
Therefore, the molar concentration of sodium hypochlorite (NaOCl) in bleach is 0.705 mol/L.