Question

A second reaction mixture was made up in the following way:

Answer 1

A. We can calculate the initial concentrations of each by the formula:

initial concentration ci = initial volume * initial concentration / total mixture volume

where,

total mixture volume = 10 mL + 20 mL + 10 mL + 10 mL = 50 mL

ci (acetone) = 10 mL * 4.0 M / 50 mL = 0.8 M

ci (H+) = 20 mL * 1.0 M / 50 mL = 0.4 M   (note: there is only 1 H+ per 1 HCl)

ci (I2) = 10 mL * 0.0050 M / 50 mL = 0.001 M

 

B. The rate of reaction is determined to be complete when all of I2 is consumed. This is signified by complete disappearance of I2 color in the solution. The rate therefore is:

rate of reaction = 0.001 M / 120 seconds

rate of reaction = 8.33 x 10^-6 M / s