chemistry dilution question

Question

how do i calculate the concentration of silver in PPM in a 0.5M solution of AgNO3 in 5% HNO3 solution. The answer should be in PPM

Answer 1

A ppm is a part per million, but there can be varying interpretation on the units. It can be:

• mg of chemical per kg of sample
• or for solutions mg of solute per liter of solution

 

I am going to go with the second one since you have a solution. So, in essence, you are looking for:

 

?mg Ag             where "soln" means solution

L soln

 

The only value that is remotely close to that type of information is the 0.5M of AgNO3 (0.5mol AgNO3/L soln). At this point it's simple stoichiometry:

 

?mg Ag  =  0.5mol AgNO₃   x    1mol Ag        x    #g Ag      x    1000mg Ag   
L soln          1L soln               1mol AgNO₃         1mol Ag               1g Ag

 

 

You just need to add the molar mass of Ag into that (#g),  compute and you will get mg of solute Ag (ok... it's really Ag⁺ ion) per liter of solution... one type of ppm.