"What is the percent yield of H2O from a reaction if only 40g of water was recovered by reacting H2 and O2 gas in a reaction where 50 g of water was expected to be formed as the product?" a. 0.8%
b. 80%
c. 125%
d. 75%

i think its 100

i hope this !

i think it's letter a.

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.