A sample of a gas has a volume of 145.0 L at a temperature of 30. K. What temperature would be needed for this sample to have a volume of 75.0 L, if its pressure remains constant?

What is conserved in the reaction shown below? h2(g) + cl2 (g) --> 2hcl(g)a. mass onlyb. mass and moles onlyc. mass, moles, and molecules onlyd. mass, moles, molecules, and volume