Solve the following problems. Make sure to show your answer using correct units and sig figs. 1. How many molecules are in 65 mol H_SOG?
2. How many moles is 3.47x10 molecules of water?
3. How many moles is 6.74x10^formula units of CaSO,?
4. How many moles are in 3.2x10- atoms of bromine?
5. How many atoms is 8.23 moles of copper (ll) chloride?

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.

Which description best characterizes the motion of particles in a solid?

In a heat of an engine, if 700 j enters the system, and the piston does 400 j of work what is the final internal (thermal) energy of the system if the initial energy is 1,500 j