6. Challenge yourself: Suppose you wanted to make 100 grams of water. A.
What is the molar mass of water (H2O)?
B.
How many moles of water are in 100 grams?
C.
How many moles of hydrogen will you need?
D.
How many moles of oxygen will you need?
How many grams of hydrogen and oxygen will you need?
F.
Is your answer reasonable? Why or why not?

Ionic compounds are made of ions, and yet the overall charge of an ionic compound is neutral. why?

There are main groups in the modern periodic table of elements

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.