Ch.13 - Chemical KineticsWorksheetSee all chapters
All Chapters
Ch.1 - Intro to General Chemistry
Ch.2 - Atoms & Elements
Ch.3 - Chemical Reactions
BONUS: Lab Techniques and Procedures
BONUS: Mathematical Operations and Functions
Ch.4 - Chemical Quantities & Aqueous Reactions
Ch.5 - Gases
Ch.6 - Thermochemistry
Ch.7 - Quantum Mechanics
Ch.8 - Periodic Properties of the Elements
Ch.9 - Bonding & Molecular Structure
Ch.10 - Molecular Shapes & Valence Bond Theory
Ch.11 - Liquids, Solids & Intermolecular Forces
Ch.12 - Solutions
Ch.13 - Chemical Kinetics
Ch.14 - Chemical Equilibrium
Ch.15 - Acid and Base Equilibrium
Ch.16 - Aqueous Equilibrium
Ch. 17 - Chemical Thermodynamics
Ch.18 - Electrochemistry
Ch.19 - Nuclear Chemistry
Ch.20 - Organic Chemistry
Ch.22 - Chemistry of the Nonmetals
Ch.23 - Transition Metals and Coordination Compounds

Solution: Homogeneous catalysis. Effect of catalyst on the speed of hydrogen peroxide decomposition to water and oxygen gas.Why does the solution in the middle cylinder have a brownish color?

Problem

At the initial time, a solid NaBr catalyst is about to be added to the reaction mixture in a graduated cylinder containing H2O2 (aqueous) in acidic solution. The solution is clear. At an intermediate time, the solution in the graduated cylinder has turned brown. The reaction is 2 Br- (aqueous) plus H2O2 (aqueous) plus 2 H+ (aqueous) goes to Br2 (aqueous, brown) plus 2 H2O (liquid). At the final time, the solution in the cylinder is again clear and there are bubbles near the surface. The reaction is Br2 (aqueous) plus H2O2 (aqueous) goes to 2 Br- (aqueous, colorless) 2 H+ (aqueous) plus O2 (gas, bubbles).


Homogeneous catalysis. Effect of catalyst on the speed of hydrogen peroxide decomposition to water and oxygen gas.

Why does the solution in the middle cylinder have a brownish color?