Given the equation representing a phase change at equilibrium:
h2o(s) < ==> h2o(l)
which statement describes this equilibrium?
(1) the h2o(s) melts faster than the h2o(l) freezes.
(2) the h2o(l) freezes faster than the h2o(s) melts.
(3) the mass of h2o(s) must equal the mass of h2o(l).
(4) the mass of h2o(l) and the mass of h2o(s) each remain constant.

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.

In a reaction equation, where are the products located? a.) above the arrow b.) to the right of the arrow c.) to the left of the arrow d.) below the arrow

How many grams of oxygen gas are contained in a 15 l sample at 1.02 atm and 28°c? show your work.