Question

Household bleach is an aqueous solution of sodium hypochlorite (NaClO). For a kinetics experiment, 4 mL of a 5% (w/w) bleach solution was diluted in a 100 mL volumetric flask. 6 mL of this diluted solution is added to 6 mL of dye in a reaction vessel. What is the concentration of bleach (in M) in the reaction vessel? Assume the density of the bleach solution is 1.11 g/mL.

Answer 1

Step-by-step explanation:

• Given Mass of 4mL of bleach solution = 4mL x 1.11 g/mL = 4.44g

• Mass of NaClO in 4.44g beach solution = 0.05 x 100 / 4.44g =1.126g

• Moles of NaClO = mass /molar mass

• molar mass of NaClO = 74.44g/mol

• moles = 1.126g/74.44g/mol = 0.0151moles

Now when 6mL of this solution is taken, moles of NaClO in this 6mL;

= 6mL x 0.0151moles /100mL = 0.000906moles

• This is added to 6mL dye. Therefore, total volume of solution = 12mL total volume = 0.012L

• hence, concentration of bleach (in M) in the reaction vessel ; number of moles/volume

• = 0.000906moles/0.012L

• = 0.0755M