chemiluminescence

kinetics lab for 46

what is an excited state?

where an electron has been
promoted to an energy level (orbital) above the ground state.

what happens when an electron returns to the ground state?

Light is emitted

what is used in the exp to move luminol from the ground to excited state

an oxidizing agent

what is the wavelength of light emitted from transitioning states proportional to

the difference in energy levels between the excited and ground state

luminol chemical compound

C₈H₇N₃O₂

sodium hydroxide

1.0 M solution, highly corrosive base

sodium hypochlorite

0.5% solution, oxidizing agent in reacting

chlorine gas

toxic gas, causes severe respiratory distress.

Potassium Ferricyanide

releases toxic cyanide gas when mixed with acids.

base (sodium hydroxide)

substance that deprotonates luminol, enhancing reactivity.

catalysts

substances that increase reaction rate without being consumed. (provide an alternate pathway for the rxn, lowering E_a)

fluorescein

chemical used to alter wavelength of emitted light.

forensic applications

using luminol to detect blood traces at crime scenes. (luminol binds to blood through the iron atoms in hemoglobin).

what is done in the first experiment

observe luminol glow and analyze temperature effects.

what is done in experiment 2

investigate catalysts' effects on reaction intensity and duration.

what is done in experiment 3

detect simulated blood stains using chemiluminescence.

what is done in experiment 4

study gas production's effect on chemiluminescence and foam.

temperature dependence

lower temperatures slow reactions, increasing glow duration.

exothermic reaction

releases heat, indicated by light emission

endothermic reaction

absorbs heat, affecting light emission duration

photon energy

energy calculated from wavelength of emitted light.

false positives

incorrect results due to substances like bleach.

false negatives

missed detections from cleaned surfaces

gas production

releases oxygen, affecting reaction dynamics.

soap solution

traps gas to create foam in reactions.

luminol hazards

skin irritant

fluorescein rxn color

yellow

luminol rxn color

blue

CHECK TUBING FOR HOLES!!!!

run water through and see