Question

a water sample is found to have a cl- content of 100ppm as nacl what is the concentration of chloride in moles per liter

Answer 1

The concentration of chloride ion is
`2.82*10^(-3)\;mol/L`

Step-by-step explanation:

We know that 1 ppm is equal to 1 mg/L.

So, the
`Cl^-` content 100 ppm suggests the presence of 100 mg of
`Cl^-` in 1 L of solution.

The molar mass of
`Cl^-` is equal to the molar mass of Cl atom as the mass of the excess electron in
`Cl^-` is negligible as compared to the mass of Cl atom.

So, the molar mass of
`Cl^-` is 35.453 g/mol.

Number of moles = (Mass)/(Molar mass)

Hence, the number of moles (N) of
`Cl^-` present in 100 mg (0.100 g) of
`Cl^-` is calculated as shown below:

`N=(0.100\;g)/(35.453\;g/mol)=2.82* 10^(-3)\;mol`

So, there is
`2.82*10^(-3)\;mol` of
`Cl^-` present in 1 L of solution.