Sulfur hexafluoride gas is collected at in an evacuated flask with a measured volume of . When all the gas has been collected, the pressure in the flask is measured to be . Calculate the mass and number of moles of sulfur hexafluoride gas that were collected. Be sure your answer has the correct number of significant digits.

The small bags of silica gel you often see in a new shoe box are placed there to control humidity. despite its name, silica gel is a solid. it is a chemically inert, highly porous, amorphous form of sio2. because water vapor readily adsorbs onto the surface of silica gel, it acts as a desiccant. despite not knowing mechanistic details of the adsorption of water onto silica gel, from the information provided you should be able to make an educated guess about the thermodynamic characteristics of the process. predict the signs for δg, δh, and δs for the adsorption of water.