Download presentation
Presentation is loading. Please wait.
Published byUrsula Goodman Modified over 8 years ago
1
Oxidation of Phosphorus Phosphorus spontaneously combines with oxygen in the atmosphere
2
Demonstration The lump of phosphorus burned with no outside initiation, demonstrating a combustion reaction The film of phosphorus did not burn but glowed, demonstrating photoemission
3
Purpose To observe a combination reaction involving phosphorus and atmospheric oxygen To compare the behavior of a lump of phosphorus to a thin film of phosphorus
4
Concepts 1.Combination Reactions 2.Reaction Kinetics 3.Photoemission
5
1.Combination Reactions In both demonstrations phosphorus combines with oxygen from the atmosphere Combination reactions have the general form A+BC The chemical equation is P 4 +5O 2 P 4 O 10 the reaction is exothermic the name of the product is tetraphosphorous pentoxide
6
2.Reaction Kinetics Since both demonstrations involve the same chemical reaction they both are exothermic Since in the lump the phosphorus is not dispersed the heat of reaction is intense enough to speed the reaction and to cause the lump to burst into flame When the phosphorus is spread thinly the heat dissipates and photoemission is able to be observed
7
3.Photoemission The emission of light by a substance In this demonstration it is a greenish glow Caused by a substance in the excited state having high energy electrons giving off visible energy when the electrons return to the ground state
8
Conclusions The concentration of a compound influenced the rate at which it reacted Different effects were observed depending on the concentration combustion or photoemission
9
Comments The phosphorus was dissolved in a solvent then dispersed in mineral oil before spreading The intermediate species responsible for photoemission is PO which is ultimately converted to P 4 O 10
Similar presentations
© 2025 SlidePlayer.com. Inc.
All rights reserved.