A 15 L tank of methane is kept at a pressure of at -12°C. If the temperature was dropped to -43 C and 855 kPa, what was the original pressure?

Compare the valence electron configuration of the nobles gas elements seen here. what statement is correct?

Two nitro no2 groups are chemically bonded to a patch of surface. they can't move to another location on the surface, but they can rotate (see sketch at right). it turns out that the amount of rotational kinetic energy each no2 group can have is required to be a multiple of ε, where =ε×1.010−24 j. in other words, each no2 group could have ε of rotational kinetic energy, or 2ε, or 3ε, and so forth — but it cannot have just any old amount of rotational kinetic energy. suppose the total rotational kinetic energy in this system is initially known to be 32ε. then, some heat is removed from the system, and the total rotational kinetic energy falls to 18ε. calculate the change in entropy. round your answer to 3 significant digits, and be sure it has the correct unit symbol.

Acompound has a molecular weight of 12.124 atomic mass units and the empirical formula c3h40. what is the molecular formula of the compound?