Question

QUESTION 6

The next five problems are calculational in nature. The initial problem statement in each case is similar but the numbers will be different. In several cases, you have more information than you need. Be sure to answer only the question asked in each case - don't get carried away. It is found in an attempt to determine the mass percentage of sodium hypochlorite that 14.81 mL of 0.19 M thiosulfate are required to reach the endpoint in the titration of 2.25 g of bleach sample. How many moles of thiosulfate ion were delivered? Include units of mol with your answer and report it to at least five decimal places.

QUESTION 7

It is found in an attempt to determine the mass percentage of sodium hypochlorite that 13.34 mL of 0.192 M thiosulfate are required to reach the endpoint in the titration of 2.16 g of bleach sample. How many moles of triiodide ion must have been in the solution being analyzed? Include units of mol with your answer and report it to at least five decimal places.

QUESTION 8

It is found in an attempt to determine the mass percentage of sodium hypochlorite that 14.35 mL of 0.194 M thiosulfate are required to reach the endpoint in the titration of 2.07 g of bleach sample. How many moles of hypochlorite ion must have been in the solution being analyzed? Include units of mol with your answer and report it to at least five decimal places.

QUESTION 9

It is found in an attempt to determine the mass percentage of sodium hypochlorite that 13.8 mL of 0.202 M thiosulfate are required to reach the endpoint in the titration of 2.23 g of bleach sample. How many moles of sodium hypochlorite must have been in the solution being analyzed? Include units of mol with your answer and report it to at least five decimal places.

QUESTION 10

It is found in an attempt to determine the mass percentage of sodium hypochlorite that 14.78 mL of 0.201 M thiosulfate are required to reach the endpoint in the titration of 2.28 g of bleach sample. What is the mass percentage of sodium hypochlorite in the bleach being analyzed? Include units of % with your answer and report it to at least the hundredths place.

Answer 1

The reaction is a type of iodometric titration which is a type of back titration in which the bleach sample us treated with Iodide ion. The hypochlorite present in the bleach reacts with the iodide ion to liberate iodine or triiodide ion which on titration with sodium thiosulfate using starch as indicator reduces the iodine and the amount of hypochlorite present can be estimated.