Methane (ch4, 16.05 g/mol) reacts with oxygen to form carbon dioxide (co2, 44.01 g/mol) and water (h2o, 18.02 g/mol). assume that you design a system for converting methane to carbon dioxide and water. to test the efficiency of the system in the laboratory, you burn 5.00 g methane. the actual yield is 6.10 g water. what is your percent yield?

Consider the story you just read. all but one of the choices below indicate that something is living.

Observation and experimentation have led many scientists to accept a theory about the origin of the universe. this theory is called the big bang theory. scientific evidence collected and observed by scientists around the world suggests that the universe is ever expanding from a hot and dense initial state. what makes this a scientific theory? (2 points)

An uncovered pot of water lies out in the sun. which statements correctly describe what happens at the surface of the liquid water? 1. the vapor pressure remains constant regardless of the water temperature. 2. the vapor pressure is produced by water molecules that have evaporated. 3. the vapor pressure increases as the sun heats the water in the pot. 4. evaporation stops once the vapor pressure reaches a certain point. 5. evaporation and condensation both occur on the liquid’s surface.