1. how many liters of o2 are needed to react completely with 45.0 l of h2s at stp? 2h2s(g) + 3o2(g) > 2so2(g) + 2h2o(g) 2. describe the shapes and relative energies of the s, p, d, and f atomic orbitals. 3. explain how atoms (ions) are held together in an ionic bond. give the example of an ionic compound. show all work .

1. 45.0 L H2S ( 1 mol / 22.4 L) ( 3 mol O2 / 2 mol H2S ) ( 22.4 L / 1 mol ) = 67.5 L O2 needed

2.s- sphere, holds 2; p- dun bell, holds 6; d- complex, holds 10; f- very complex, holds 14

3.In an ionic bond, oppositely charged ions are held together by the electronic force of attraction that exists between oppositely charged particles. In the ionic compound, anions and cations are present in a ratio that causes the total charge on the compound to be zero. Sodium phosphide, Na3 P, has three sodium ions for each phosphide ion. This ratio insures a zero total charge given the charges on the two individual ions (Na = 1+, P = 3-).

Spontaneity tell us the direction of the reaction, but not how fast it goes. gibbs free energy brings together enthalpy, entropy and temperature in one easy formula. g = h - ts. and, finally the sign of delta g is always negative for a spontaneous reaction.