How many moles of hcl are needed to form 20 moles of cl2 gas?

When a scientific theory has been tested and proved by the scientific community, it becomes a law

650.j is the same amount of energy as? 2720cal1550cal650.cal2.72cal

What would be the original temperature of a gas that has a volume of 2.0 l and a pressure of 2.0 atm and an unknown temperature that the volume increased to 3.5 l in its pressure decreased to 1.0 atm if the final temperature is measured to be 11°c