Question

The federal limit for cadmium in drinking water is 0.010 mg per liter of solution. What is the molar concentration of a Cd solution that has reached the limit?

Answer 1

`M=8.9x10^(-8)M`

Step-by-step explanation:

Hello,

In this case, one can assume 1L as the volume of the solution, so we've got 0.010mg of cadmium. Now, as we're asked to know its molarity, one computes the moles of cadmium as follows:

`n_(Cd)=0.010mg*(1x10^(-3)gCd)/(1mgCd)*(1molCd)/(112.4gCd)=8.9x10^(-8)molCd`

Now, one obtains the molar concentration (molarity) as shown below:
`M=(8.9x10^(-8)molCd)/(1L)\\ M=8.9x10^(-8)M`

Best regards.

Answer 2

Thank you for posting your question here. The molar concentration of a Cd solution that has reached the limit is 8.89x10^-8 mols/L. The equation to be used M=n/L to solve the above problem. Below is the solution:

.010mg/L = .00001g/L
.00001g / 112.41g/mol = 8.89x10^-8 mols/L