the value of n in the molecular formulaBenAl2Si6O18is

This is the example of cyclic silicate with the general formula (SiO3)n2n-

Since there are 6 silicon atoms thus -2n = -12, to balance the charge beryllium and aluminium are present. Aluminium has +3 charge and there are two aluminium atoms thus +6 charge is balanced .now + 6 charge is left which has to be balanced by beryllium. Be has +2 charge thus, there should be three beryllium atoms to balance the whole molecule. Thus n=3.

 

 

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Arun (askIITians forum expert)