PC13(0) + Cl2(g) 2PCi5C) Kc6.5 At a certain point in time, a 1.00 L rigid reaction vessel contains 1.5 mol of PC13(a). 1.0 mol of Cl2C), and 2.5 mol of PCI5C). Which of the following describes how the measured pressure in the
reaction vessel will change and why it will change that way as the reaction system approaches equilibrium at constant temperature?
The pressure will increase because Q< KC.
B
The pressure will increase because > K.
The pressure will decrease because Q< KC.
The pressure will decrease because > Kc.
D

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

explanation: chemical change is the change in which chemical composition of the substance changes. physical change is the change in which there is no change in chemical composition.

chemical changes are accompanied by following changes:

a) precipitate formation

b) energy is released or absorbed

c) formation of bubbles

d) change in color

as it is given that the red color has disappeared and there is production of gas, it means the red substance has undergone a chemical change.

e