How does particles of substance behave at its melting point?

When a substance is heated, its atoms gain energy and begin to vibrate rapidly within the lattice of the substance (the substance expands). As more heating continues, the atoms gain even more energy and move more rapidly until they are able to overcome the force of the bonds, that hold the atoms together in the lattice, until the structure is disrupted.  

did anyone actually do this? like if anyone has submitted this i rly need .

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