Two isotopes of element X have average atomic mass of 54 amu. Which numerical setup can be used to determine the atomic mass of naturally occurring boron? 1)80% of 50X and 20% of 55
2)20% of 50X and 80% of 55X
3)50% of 50X and 50% of 55X
4)75 of 50X and 25% of 55X

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

im doing test rn im going with 2 but ill give answer if itss wrong,   : )