In the chemistry laboratory why do scientists use a mortal and pestle

To increase surface area of a solute. 
The mortar and pestle can make the solute from bulk to powder. 
So the surface area will increase and the reaction rate or dissolving rate will also increase.

Oh nskskakaaka

Ch4 and ph3 are both covalent since they are composed both of non-metals.    ch4 is non- polar because of  london forces and has a geometry of tetrahedral  ph3 , on the other hand, is umbrella shaped polar and has dipole-dipole intermolecular force (imf) . since ph3 is polar, it has a stronger imf