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?

pv=nrt

explanation:

answer: semi-infinite solid initially at a uniform temperature of 400 ◦c is cooled at its surface by convection. the cooling fluid at a constant temperature of 200 ◦c has a convective coefficient (ha) of 250 w/m2.k. the physical properties of the solid: k = 20 w/m.k and α = 4 * 10-5  m2/s. using δx = 0.04 m and δt = 10 s. write the finite difference equations describing the transient heat transfer of the first five δx and the temperature profile after 30 s.