Should hydrogen be classified as a member of group 1, group 17, or is it unique? explain your reasoning behind your choice.

Honestly, while Hydrogen appears to be in group 1, it really isn't. It is unique, and has no characteristics similar to others, especially to the alkali metals in group 1 and halogens in group 17.  

Hydrogen only shares one thing with alkali metals. It has one electron in the outermost shell, and has a valency of one. As far as halogens go, Hydrogen is a reducing agent, and halogens are known for being oxidizing agents.

So, I can say that more research needs to be done on Hydrogen. In the meantime, it is quite unique. Thanks!

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