Question

Experimental Procedure, Part F. A 1.0- mL volume of 0.010 M H2SO3 is added to a mixture of 12 drops of 0.01 M HIO3, 8 drops of deionized water, and 1 drop of starch solution. A color change in the reaction mixture occured in 40 seconds.

a. Assuming 25 drops per milliliter, determine the initial molar concentration of IO3- after the mixing but before any reaction occurs (at time = 0).

b. At the same point in time, what is the molar concentration of H2SO3?

c. The rate of the reaction is measured by the disappearance of H2SO3. For the reaction mixture in this question, what is the reaction rate? Express the reaction rate with appropriate units.

Answer 1

a.
25 drops/mL means the 1.0 mL sample is 25 drops. Total drops = 25 + 12 + 8 + 1 = 46
concn HIO3 = 0.01 x (12 drops/46 drops) = ??

b.
concn H2SO3 = 0.01 x (25 drops/46 drops) = ??

c.
rate rxn = 1/5 rate disappearance H2SO3. You need a balanced equation for this and it is as follows but check me out on this.
2HIO3 + 5H2SO3 ==> I2 + 5H2SO4 + H2O