Consider the following intermediate chemical equations. 2 equations. First: 2 upper P (s) plus 3 upper C l subscript 2 (g) right arrow 2 upper P upper C l subscript 3 (l). Second: upper P upper C l subscript 3 (l) plus upper C l subscript 2 (g) right arrow upper P upper C l subscript 5 (s).

When you combine the intermediate chemical equations, which substance do you cancel out?