At constant pressure, which of these systems do work on the surroundings?

constant-pressure

#1

At constant pressure, which of these systems do work on the surroundings? Check all that apply.

  1. 2A(g) + 3B(g) —> 4C (g)
  2. A(s) + B(s) --> C (g)
  3. 2A(g) + 2B(g) —> 3C(g)
  4. 2A(g) +B(g) —> 4C(g)

Answer:

sum of moles of gas on left side should be greater than the right side
so,

  1. Works , 5>4
  2. Not work , 0<1
  3. Works , 4>3
  4. Not work , 3<4