A1.0 ml volume of 0.010 m h2so4 is added to a mixture of 6 drops of 0.010 m hio3, 14 drops of deionized water, and 1 drop of starch solution. a color change in the reaction mixture occurred after 56 seconds. a.) assuming 20 drops per milliliter for all solutions, determine the initial molar concentration of hio3 after the mixing but before any reaction occurs (at time = 0). b. )the rate of the reaction is measured by the disappearance of hio3. for the reaction mixture in this question, what is the reaction rate? express the reaction rate in units of mol hio3/l / sec to correct sig. figs.

a) Volume of H₂SO₄ = 1.0 ml

Volume of HIO₃ = 6/20 × 1 = 0.30 ml

Volume of H₂O = 14/20 × 1 = 0.70 ml

Volume of starch = 1/20 × 1 = 0.05 ml

Total volume of solution = 1 + 0.30 + 0.70 + 0.05 = 2.05 ml = 0.00205L

Moles of HIO₃ = Stock volume × Stock concentration of HIO₃

= 0.30/1000 × 0.010 = 3.0 × 10⁻⁶ mol

Initial concentration of HIO₃ = moles of HIO₃ / Total volume

= 3.0 × 10⁻⁶ / 0.00205

= 1.46 × 10⁻³ M

b) In 56 seconds, the concentration of HIO₃ diminishes from 0.010 mol/L to 0 mol/L.

Thus, in 1 sec decrease in concentration:

= 0.010 /56s = 1.7857 × 10⁻⁴ mol/L/s

The rate of reaction = 1/2 d/dt [HIO₃] = 1.7857 × 10⁻⁴ mol/L/s /2

= 8.9 × 10⁻³ mol/L/s