Calculate the molarity of the commercial bleach before it was diluted. bleach 6.25%
6.25%. Is that w/w or w/v? (I have two bottles at home; both say 6.50% but neither specifies w/w or w/v.) Assuming w/v, it means 6.25g NaClO/100 mL soln.
6.25/molar mass NaClO = moles NaClO.
That x 10 will be moles in 1000 mL which will be the molarity.
To calculate the molarity of the commercial bleach before it was diluted, we first need to determine the concentration of bleach in terms of moles per liter.
1. Start by converting the percentage concentration of bleach to a decimal: 6.25% = 0.0625.
2. Assume we have 100 mL of the bleach. Convert this to liters: 100 mL = 0.1 L.
3. Now, we need to determine the number of moles of bleach present in the 0.1 L. To do this, we need to know the molar mass of bleach. The molar mass of sodium hypochlorite (NaClO), the active ingredient in bleach, is approximately 74.44 g/mol.
4. Calculate the number of moles by multiplying the mass (in grams) by the reciprocal of the molar mass:
Moles = Mass (in grams) / Molar mass
Since the percentage concentration is based on weight/volume, we need to calculate the mass of bleach in grams.
Mass = Percentage concentration * Volume
Mass = 0.0625 * 0.1 L = 0.00625 g
Moles = 0.00625 g / 74.44 g/mol ≈ 0.000084 moles
5. Finally, calculate the molarity by dividing the moles by the volume in liters:
Molarity = Moles / Volume (in liters)
Molarity = 0.000084 moles / 0.1 L ≈ 0.00084 M
Therefore, the molarity of the commercial bleach before it was diluted is approximately 0.00084 M.