Thursday
May 5, 2016

# Homework Help: chemistry

Posted by Krisha on Wednesday, July 20, 2011 at 9:35pm.

RATE = ([ Na2S2O3]/time) = k [I-]a [BrO3-]b [HCl]c
1A) You mix together in the proper manner the following:

10.0 mL of .0100 M Potassium Iodide
10.0 mL of .00100 M Sodium thiosulfate
10.0 mL of water
10.0 mL of .0400 M Potassium Bromate
10.0 mL of .100 M HCl
The time to turn blue is... 84 sec

1B) You also mix together in the proper manner the following:
10.0 mL of .0100 M Potassium Iodide
10.0 mL of .00100 M Sodium thiosulfate
20.0 mL of .0400 M Potassium Bromate
10.0 mL of .100 M HCl
The time to turn blue is... 22 sec

Calculate
The Experimental value of exponent a..._______________ (a)
2) If the exponents a, b, and c have the values:
a = 0; b = 2; c = 1
CALCULATE:
Rate constant k for data in 1A...______________ (b)

3) You mix together in the proper manner the following VOLUMES:
0.0100 M Potassium iodide...8.3 mL
0.0010 M Sodium thiosulfate...8.3 mL
Distilled water...18.0 mL
0.0400 M Potassium Bromate...6.9 mL
0.100 M Hydrochloric acid...5.7 mL
Using the rate constant and rate equation from problem 2),

CALCULATE the time to turn blue...__________________ sec (c)
4) A plot of log Rate vs 1/T gives a best straight line which goes through....
1/T = 0.00300, log rate = -4.20
and 1/T = 0.00395, log rate = -6.00.
CALCULATE:
The Slope of the line..._____________ (d)

The Activation Energy (Ea) (Kj/mol)...________________(e)