Question

9th class que...........
the number of Gram moles of aluminium ions present in 0.051 gram of Aluminium oxide is-
(a) 0.001
(b) 0.051
(c) 0.102
(d) 2
please reply fast

Answer 1

mass of one mole of Aluminium oxide (Al2O3)= 2(mass of Al) + 3(mass of O)
= 2×27 +3×16
=54 +48
=102 grams
1mole = 102 grams

1 mole of Al2O3 contains 54 gram Al
102 grams of Al2O3 = 54 gram Al
1 gram of Al2O3 = 54/102 grams Al
0.051 grams of Al2O3= 54 × 0.051/102
= 0.027

No. of gram = Mass / molar mass
= 0.027/ 27
= 0.001