Mass Transfer
In a moderately sized packed absorption tower, channeling (which is most severe with stacked packings) can be minimised by taking the ratio of tower diameter to packing diameter

< 8 : 1
> 8:1
> 4 :1
< 6:1

ANSWER DOWNLOAD EXAMIANS APP

Mass Transfer
In a counter-current liquid extractor

Both liquids flow at fixed rate
Both liquids can have any desired flow rate
Only one of the liquids may be pumped at any desired rate
Liquid's flow rate depends upon the temperature and pressure

ANSWER DOWNLOAD EXAMIANS APP