Given the equation deltaG = deltaH - T deltaS, which set of conditions would result in a reaction that is unambiguously nonspontaneous? A. entropy decreases and the reaction is endothermic B. entropy increases and the reaction is exothermic C. entropy stays the same and there is no change in enthalpy D. entropy decreases and the reaction is exothermic

catya your not at all which answer i've seen you do this on another question!

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.