If you are using 5.25% (mass/mass) bleach solution and you determine that the density of the bleach solution is 1.08 g/mL, how many moles of sodium hypochlorite are present in a 4.00 mL sample?
To determine the number of moles of sodium hypochlorite present in the 4.00 mL sample, we need to use the following formula:
moles = (mass / molar mass) = (volume x density / molar mass)
First, we need to calculate the mass of the bleach solution in the 4.00 mL sample:
mass = volume x density
mass = 4.00 mL x 1.08 g/mL
mass ≈ 4.32 g
Next, we need to calculate the molar mass of sodium hypochlorite (NaClO):
molar mass of Na = 22.99 g/mol
molar mass of Cl = 35.45 g/mol
molar mass of O = 16.00 g/mol
molar mass of NaClO = molar mass of Na + molar mass of Cl + molar mass of O
= 22.99 g/mol + 35.45 g/mol + 16.00 g/mol
≈ 74.44 g/mol
Now we can calculate the number of moles of sodium hypochlorite:
moles = (mass / molar mass)
= (4.32 g / 74.44 g/mol)
≈ 0.058 moles
Therefore, there are approximately 0.058 moles of sodium hypochlorite present in the 4.00 mL sample.