Question #25b38

1 Answer
May 25, 2016

Answer:

#Al_2(SiO_3)_3#

Explanation:

We can proceed by calculating masses of elements X,Y and Z present in the molar mass of the compound #X_2(YZ_3)_3#
using the given percentage composition of the compound.
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So mass of X present in one mole of the compound is #282.23xx19.12%g=53.96g#
Since according to the formula of the comound its molecule contains 2 atoms of X ,
#"the molar mass of X"=53.96/2=26.98g/"mol"#
Now from periodic table it is found that X is nothing but Al.

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Similarly mass of Y in molar mass of the compound is
#282.23xx29.86%=84.27g#.
As the molecule contains 3 atoms of Y,
#"molar mass of Y"=84.27/3=28.09g/"mol"#
According to periodic table it should be Si.

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Now finally 9 atoms of y are present in one molecule of the comound and its mass in one mole of the compound is
#282.23xx51.02%~~144g#
Hence#" ""molar mass of Z"= 144/9=16g/"mol"#
Consulting periodic table we can say the element Z is Oxygen O

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So the compound will have formula #Al_2(SiO_3)_3# which is Aluminium silicate