$5.$Which moment of RTD represents the skewness of the distribution?

A$)$ First moment

B$)$ Second moment

C$)$ Third moment

D$)$ Fourth moment

What is the shape of the C curve for an ideal CSTR$?$

A$)$ Exponential

B$)$ Gaussian

C$)$ Uniform

D$)$ Parabolic

Which of the following reactors has the longest mean residence time?

A$)$ Ideal batch reactor

B$)$ Ideal CSTR

C$)$ Ideal PFR

D$)$ Plug flow reactor

Which curve characterizes the RTD of an ideal plug flow reactor?

A$)$ C curve

B$)$ E curve

C$)$ F curve

D$)$ Plug curve