Chemistry, asked by geetika3, 1 year ago

plzzz answer fast.

calculate the number of aluminium ion present in 0.051g of aluminium oxide.


question from class 9 NCERT ch 3 back exercise. plz give a full explanation. plz overlook the question if you don't know the answer.

Answers

Answered by sabicoolz
4
the number of aluminium ion present in 0.051g of aluminium oxide =
Attachments:

geetika3: in the second step of answer why the Avogadro no. is multiplied by 2??
sabicoolz: No. of Al(3+) ions in one molecule of Al2O3 = 2
geetika3: so thats why its multiplied by 2
sabicoolz: yup
geetika3: ok
geetika3: thank you so much
sabicoolz: u r wlcm
Devika1243: why it is multiplied by 2
Answered by abhi178
2
molecular formula aluminum oxide =Al2O3

molecular mass of Al2O3 = 102 g

no of mole of Al2O3 = given wt/molecular wt

= 0.051/102 = 1/2 x 10^-3

= 5 x 10^-4

in one mole of Al2O3 , 2mole of Al+3 ions present .

so , 5 x 10^-4 mole of Al2O3 , 2 x 5 x 10^-4 = 10^-3 mole of Al+3 ions present .

we know ,

no of ions = no of mole × 6.023 x 10^23

so,
no of ions of Al+3 in Al2O3 = 10^-3 x 6.023 x 10^23 = 6.023 x 10^20
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