Consider the full set of reactions required to purify zinc metal. Step 1: ZnCO3 + heat → ZnO + CO2 Step 2: ZnO + C + heat → Zn + CO How do the oxidation numbers of Zn and C change throughout these two reactions? Which compound is the oxidizing agent and which is the reducing agent in each step?

Answer asap need by wednesday morning explain how a buffer works, using an ethanoic acid/sodium ethanoate system including how the system resists changes in ph upon addition of a small amount of base and upon addition of a small amount of acid respectively. include the following calculations in your i. calculate the ph of a solution made by mixing 25cm3 0.1m ch3cooh and 40cm3 0.1m ch3coo-na+. [ka = 1.74 x 10-5 m] ii. calculate the ph following the addition of a 10cm3 portion of 0.08 m naoh to 500cm3 of this buffer solution. iii. calculate the ph following the addition of a 10cm3 portion of 0.08 m hcl to 200cm3 of the original buffer solution.