For the following titration curve, 25 mL of a polyprotic acid was titrated with a known concentration of base: Fill in either EQ for Equivalence Point or ½ EQ for the half-equivalence point in the boxes (A-D) provided. If the base concentration is 0.175M, what is the acid concentration?     

What is the oxidation number of P in PF6-? Note the charge is -1. it is a little hard to see. Answer numerically.

Hawaiian Electric’s preferred stock pays an annual dividend of $2 per share.  The preferred stock is trading at $40 per share.  Calculate the Hawaiian Electric’s cost of preferred stock.  Enter your answer expressed as a percentage but do not enter the percent sign in your answer.  For example, if you answer is 4.45%, then enter 4.45.

45 g HF is reacted with excess zinc 2HF + Zn –> H2 + ZnF2. What is the theoretical yield of ZnF2? Answer in g. Do not type units. Do not use scientific notation.

What is the enthalpy of reaction of Pb2+(aq) + 4OH-(aq) –> PbO2(s) + 2H2O(L)? Answer in kJ/mol. Do not type units. Do not use scientific notation. Please be careful with sig figs. Enthalpy of formation (kJ/mol) Pb2+ (aq) -1.7 hydroxide (aq) -230.0 PbO2 (s) -277.4 water (L) -285.83 Please be careful with sig figs.

Draw the Lewis Dot Structure of chlorate (ClO3-). How many resonance structures are in chlorate? Answer numerically.

If the OH- concentration in a bottle of an ammonia (NH3) based cleaner is 4.0 x 10-5 M, what is the H+ concentration? (Kw = 1.0 x 10-14)  

How many neutrons are in 143Nd? Answer numerically.

Calculate the solubility of solid Ca3(PO4)2 (Ksp = 1.3 x 10-32) in a 0.20 M Na3PO4 solution.

(a) What is the pH of the solution that results from the addition of 13 mL of 2.0M Na2HPO4 to 15 mL of 1.5 M of Na3PO4? (Ka = 3.6 x 10-13) (b) What is the new pH if 3.5 mL of 0.65M NaOH is added to the solution?