Three different substances, A2X, A2Y, and A2Z, were dissolved in water with the following results. (Water molecules are omitted for clarity.) Which of the substances is the strongest electrolyte, and which is the weakest?  

Given:   S (s) + O2 (g) → SO2 (g)                           ΔH° = – 296.1 kJ              2 SO3 (g) → 2 SO2 (g) + O2 (g)                 ΔH° = +198.2 kJ   Find ΔH° for : 2 S(s) + 3 O2(g) → 2 SO3(g)  

What is the maximum mass of PO2 that is formed when 6.8 g of P2O5 are consumed? 2 P2O5

The molecular geometry of ________ is NOT tetrahedral

Give the ground state electron configuration for As.  

What mass of NaI is needed to make 250.0 mL of a 0.250 M solution of NaI? [Molar Mass NaI = 149.89 g

Match the subatomic property with its description: 

Which gas is most dense at 4 atm and 300 K?

Draw the best Lewis structure for CH3- . What is the formal charge on the C?

Based on the Lewis structure of ammonia, NH3, what is the formal charge on the central atom?