Chemical Equilibrium Lab Report

Chemical Equilibrium

October 14, 2017

Introduction

This lab is centered around Le Chatelier’s Principle. In his research, he found that a chemical reaction can be manipulated to maximize yield. A change in one of the variables that describe a system at equilibrium produces a shift in the position of the equilibrium that counteracts the effect of this change. Le Chatelier's Principle describes what happens to a system when a stress is applied. Three ways in which we can change the conditions of a chemical reaction at equilibrium are: changing the concentration of one of the components of the reaction, changing the pressure on the system, and changing the temperature at which the reaction is run. The educational goal of the lab is to observe

Observations for each situation were recorded.

Results

Model 1

The concentration of the iron(III) nitrate (Fe(NO3)3) was 0.000016 M, and the concentration of the potassium thiocyanate (KSCN) was 0.000002 M. The volume of the iron(III) nitrate (Fe(NO3)3) was 2 mL, and the volume of the potassium thiocyanate (KSCN) was 2 mL. The color of the iron(III) nitrate (Fe(NO3)3) was orange, and the color of the potassium thiocyanate (KSCN) was clear. The color of the equilibrium mixture was amber. The wavelength was 401. 178. The absorbance was 0.660.

Model 2

Test tubes K, A, and B were originally pink. After the addition of HCL, test tubes A and B turned blue. With the addition of AgNO3, a white precipitate formed, and the solution returned to its original pink.

Model 3

After 3 minutes in hot water, the resulting color was blue. After 3 minutes in cold water, the resulting water was pink.

The intensity of the purple colour becomes constant on attaining equilibrium. When the concentration of any of these species is changed, the equilibrium is disturbed and the reaction quotient remains no longer equal to equilibrium value. To re-establish the equilibrium, the reaction quotient must again become equal to the equilibrium