How does VSEPR help determine the shape of the molecule? A) The shape of the molecule is determined by the mass of the nuclei of different atoms in molecule, so that the mass is as evenly distributed as possible.
B) The shape of the molecule is determined by the valence electrons of the different atoms within a molecule repelling each other, so the atoms are as far apart as possible from any other valence shell.
C) The shape of the molecule is determined by the electronegativity values of the different atoms within a molecule, so the atoms are spaced apart based on decreasing electronegativity.

B) The shape of the molecule is determined by the valence electrons of the different atoms within a molecule repelling each other, so the atoms are as far apart as possible from any other valence shell.

Explanation:

VSEPR denotes Valence Electron Pair Repulsion.

It is one of the theories used to predict the model of a compound or molecule.

as given the equation is

2al + 6 hcl > 2 alcl3 + 3 h2(g)

as per equation two moles of aluminum reacts with six moles of hcl to give two moles of alcl3 and three moles of hydrogen gas

given: three moles of al are present and 7 moles of hcl

for three moles of aluminum nine moles of hcl will be required

however as 7 moles of hcl are present so the limiting reagent is hcl

hcl is going to decide the number of moles of product formed

when six moles of hcl are present = 3 moles of h2 are formed

when one mole of hcl is present == 3/6 mole sof h2 will be formed

when 7 moles of hcl are present = 3 x 7/ 6 moles of h2 will be formed = 3.5 moles of h2