To a sample of an element A (at.wt.=70) another element B (atomic wt = 120) is to be added as an impurity. For the ratio of the atoms in the mixture to be 1:10^(-9),x xx10^(-8)g of B will be required for 35g of A. Find the value of x.

To a sample of an element A (at.wt.=70) another element B (atomic wt =

1.	To a sample of an element A (at.wt.=70) another element B (atomic wt = 120) is to be added as an impurity. For the ratio of the atoms in the mixture to be 1:10^(-9),x xx10^(-8)g of B will be required for 35g of A. Find the value of x.
Answer» Solution :`(A)/(B)=(1)/(10^(-9))` ATOMS if A = n atom = wt = `(n)/(6XX10^(23))xx70` `B = nxx10^(-9)` atoms IMPLIES wt = `(nxx10^(-9))/(6xx10^(23))xx120` given `(nxx70)/(6xx10^(23))=35implies(n)/(6xx10^(23))=(35)/(70)=(1)/(2)` `therefore (nxx10^(-9)xx120)/(6xx10^(23))=(1)/(2)xx120xx10^(-9)=6xx10^(-8)` `x=6`