2. 0.300 moles of Br2 (g) and 0.300 moles of Cl2 (g) are introduced into a 1.00 L container at 400. K and then allowed to come to equilibrium (Kp=7.0):
c
Br2 (g) + Cl2 (g) = 2 BrCl(g) ·
The total pressure in the container at equilibrium is:
(a). 9.8 atm
(b). 9.8 torr
(c). 2.00 x 103 atm
(d). 19.7 atm

Explanation is in the file

cutt.us/p>

here's the link to your question!

explanation:

answer is: c. the experiment shows that the red substance experienced a chemical change.

this is chemical change (chemical reaction), because two new substances are formed (metalig liquid and gas), the atoms are rearranged and the reaction is followed by an energy change.

this is example of chemical decomposition.

chemical decomposition (analysis) is the separation of a single chemical compound into its two or more elemental parts or to simpler compounds.  

chemical decomposition is opposite of chemical synthesis.