A sealed quartz tube at contains pure chlorine gas ( ) at an initial absolute pressure of
CHEMISTRY · Multi-part · A Level · Chemistry · Amount of substance · Amount of substance
Problem
A sealed 2.0L quartz tube at 300K contains pure chlorine gas (Cl2) at an initial absolute pressure of 0.80atm. The tube is exposed to intense ultraviolet radiation that causes every Cl2 molecule to dissociate completely into two separate chlorine atoms. The temperature is maintained at 300K throughout the process, and the gas remains ideal. Use R=0.0821Latmmol−1K−1.
(a) Determine the initial number of Cl2 molecules in the tube.
(b) Calculate the final absolute pressure in the tube after complete dissociation.
(c) Quantify the percentage change in pressure produced by the dissociation and provide a particle-level explanation for this change.