(a) Sketch a graph of the van Deemter equation (plate height versus linear flow rate). What would the curve look like if the multiple path term were 0? If the longitudinal diffusion term were 0? If the finite equilibration time term were 0?
(b) Explain why the van Deemter curve for 1.8-μm particles in Figure 24-3 is nearly flat at high flow rate. What can you say about each of the terms in the van Deemter equation for 1.8-μm particles?
(c) Explain why the 2.7-μm superficially porous particle enables separations similar to those achieved by 1.8-μm totally porous particles, but the superficially porous particle requires lower pressure.