Which of the following is an example of hydrolysis?
a. because of a reaction with water, feldspar is changed into clay minerals.
b. because of a reaction with carbonic acid, limestone is dissolved.
c. because of a reaction with acid rain, sandstone develops black surface deposits.
d. because of a reaction with oxygen, iron changes into rust.

the maximum mass of nh3 is nh3 in grams

the answer is symmetrical : )

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.