Answer to Question #342581 in General Chemistry for Kaushi

Question

The molar cconcentration of a solution of ammonium molibdate in an aqueous solution which contains 48 parts per million of MoMolybdenum is?

Answer 1

$c(Mo)=48 ppm$

It means, that it is 48 g of molibdate in 1000 l of solution.

$M(Mo)=96 g/mole$

$n(Mo)48/96=0.5 mole$

Ammonium molibdate

$(NH_4)_2 MoO_4$

contains 1 atom of molibdate in molecule. So it is 0.5 mole of ammonia molibdate in 1000 l of solution.

So molar concentration is $0.5/1000=5x10^{-4} mole/l$