Which is the valid observation for the reaction...? #3O_2(g)rarr2O_3(g)#

#"1. The mass of the products increase."#
#"2. This is an exothermic reaction."#
#"3. The pressure of the reaction mixture should DECREASE."#
#"4. The pressure of the reaction mixture should INCREASE."#

1 Answer
Oct 17, 2016

Answer:

#"Option 3"# is the best answer.

Explanation:

All chemical reactions conserve mass. If you start with 10 g of reactant, from all sources, at MOST, you can get 10 g of reactant. In practice, you are not even going to get that.

The equation clearly shows that the number of gaseous molecules is reduced; nevertheless, mass is conserved:

#3O_2(g) rarr 2O_3(g)#

And thus pressure is reduced due to the decrease in the number of gaseous particles.

#"Option 3"# certainly describes the scenario.