Agas mixture called heliox, 6.11% o2 and 93.89% he by mass, is used in scuba tanks for descents more than 65 m below the surface. calculate the mole fractions of he and o2 in this mixture. he is 0.9980

Asolution at 25 degrees celsius is 1.0 × 10–5 m h3o+. what is the concentration of oh– in this solution?

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.

Particle model to predict what will happen if a sharp object creates a hole in the soccer ball