Mg + 2hcl → mgcl2 + h2
how many molecules

The total number of molecules taking pert in the given reaction is 3.

Explanation:

There are two reactant molecules participating in the given reaction

  Mg+2HCL=MgCl2+H2

Here 1 molecule of magnesium(Mg) and 2 molecules of Hydrochloric acid(HCl) undergoing chemical reaction to generate magnesium chloride(MgCl2) and hydrogen gas(H2).

       As a result the molecularity of the reaction is 3.

phaneritic textures in which phaner means visible so phaneritic textures are standard of impertinent volcanic rocks. these rocks crystallized gradually under the surface of earth. when the magma cools deliberately then the ores have chance to develop and produce long crystals.