[nisha1]

Sir, can you please explain me how to find the mass flow rate of a perticular substance.
For example if we pack any material (like activated charcoal) in a dropping cylinder. Say if the height of packing is 2cm and diameter is 3cm, and any solution of 1N is percolated through the packed material at a rate of 1mL/min. What will be the flow rate?

[Hunt]

The massflow rate is the amount of mass passing through a specific area A per unit of time. It can be directly calculated from the volume flow rate times the density.

m.f.r = v.f.r x p

[typhoon2028]

The massflow rate is the amount of mass passing through a specific area A per unit of time. It can be directly calculated from the volume flow rate times the density.

m.f.r = v.f.r x p

or you can do a timed catch.  By weighing how much is dripping in a minute or so time.

[nisha1]

The massflow rate is the amount of mass passing through a specific area A per unit of time. It can be directly calculated from the volume flow rate times the density.

m.f.r = v.f.r x p

sir, the value of density is not given. but if we go with the defintion - massflow rate is the amount of mass passing through a specific area A per unit of time, then:
If 100mL of NaOH solution (1N) passes through the bed in 100 min.
ie. 4gm/L of NaOH passes through 28.260cm² area of cylinder in 100 min, then-
     Mass Flow Rate= 4/28.260*100  which is coming out to be 0.00142 gm/cm² min
Am i right

[typhoon2028]

Can you place a beaker under the cylinder and weight how much liquid comes out after a minutes time?  You could then get grams/minute flow rate.

Why are you trying to include cross sectional area?