What is the oxidation number of manganese in MnO3?

What is the limiting reagent, excess reagent, and theoretical yield for the following reaction if the starting amount of A2 and Z2 are provided in the image labeled starting amounts before reaction below?

What is the sum of coefficients when the neutralization reaction occurs between chloric acid (HClO3) and calcium hydroxide (Ca(OH)2)? 

How many electrons are transferred for the following reaction when i is correctly balanced? 

HEPES buffer (C8H18N2O4S) in used for cell cultures. A researcher needs 0.0200 M of HEPES. What mass of HEPES in grams would be needed to produce 280.0 mL of solution. 

What volume in mL of 0.219 M barium hydroxide (Ba(OH)2) is required to reach the equivalence point (neutralize) 55.0 mL of 0.198 M hydroiodic acid (HI)? 

Use the following reaction identify the oxidizing and reduction agents.

A scientist measures out the following volume of stock hydrochloric acid with a concentration of 9.6 M (the volume of the stock added is shown in the figure of the graduated cylinder below with the arrow pointing to the bottom of the meniscus). The solution is diluted to a final volume of 200.0 mL, what is the final concentration of the diluted solution. 

The contribution-margin ratio is:

Mayfly LLC’s accounting records noted the following costs: Sales commissions, $65,000; plant supervision, $190,000; and administrative expenses, $185,000. Mayfly’s period costs total: