Reaction kinetics                           Honors Chemistry

background [prelab assignment (10 points) due at the beginning of the lab]

determine the exponents in the rate law for the reaction

Na₂S₂O_{3 (aq)} + HCl _(aq) --> S _(s) + SO_{2 (g)} + H₂O _(l) + NaCl _(aq)

• design an experiment
• describe the calculations

[hint:  the "end of the reaction" is when the clear solution becomes cloudy due to the formation of sulfur]

 

purpose

determine the exponents in the rate law for the following reaction (expressed as its net ionic equation):

S₂O₃^2- _(aq) + H⁺ _(aq) --> S _(s) + SO_{2 (g)} + H₂O _(l)

materials

sodium thiosulfate (0.15 M Na₂S₂O₃ * 5 H₂O); HCl (1 M)

water (to dilute the above solutions)

clear microwell plates; toothpick (to mix solutions)

your own watch (to time the reaction)

micropipet (to measure various volume of a solution)

methods / data analysis

prepare your sodium thiosulfate solution; share with another group

student design

 

Content of lab report [15 points]

data analysis (10 points)

data table of your experimental data

determine the exponents in the rate law

discussion (5 points)

which reactant has the greatest effect on the rate of the chemical reaction ?  justify your response.

resources

lab activity source (examples):  site 1  [access 4 / 2011]