Carbon tetrachloride is a solvent which is used as a refrigerant and also as a cleaning agent. Today, methane
and chlorine are mainly used to produce carbon
tetrachloride:

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