Question # If ( 1 / 2 ) moles of oxygen combine with Aluminimum to form ( mathrm{Al}_{2} mathrm{O}_{3} ) then weight of Aluminium metal used in the reaction is ( (mathrm{Al}=27)- )

# If ( 1 / 2 ) moles of oxygen combine with Aluminimum to form ( mathrm{Al}_{2} mathrm{O}_{3} ) then weight of Aluminium metal used in the reaction is ( (mathrm{Al}=27)- )

( 4 mathrm{Al}_{(mathrm{s})}+3 mathrm{O}_{2(mathrm{g})} rightarrow 2 mathrm{Al}_{2} mathrm{O}_{3(mathrm{s})} )

(1) ( 27 mathrm{g} )

(2) ( 18 mathrm{g} )

(3) ( 54 mathrm{g} )

(4) ( 40.5 mathrm{g} )

Solution

balanad ( quad lambda_{x n} )

[

4 A l+3 O_{2} rightarrow 2 A L_{2} D_{3}

]

3 molus ob ( 0_{2} ) require 4 molus of Al

0.5 moles of ( 0_{2} )

[

frac{0.5 times 4}{3}=frac{2}{3} text { moles of } mathrm{Al}

]

Mass ob ( frac{2}{3} m o L=frac{2}{3} tan x frac{27 g}{M o L}=18 g )