[enjoi]

In class we did a lab to determine chloride ion concentration in tap water. How would i go about calculating the molarity of the chloride ion concentration.

[mike]

What were the results of your experiment?

[enjoi]

We used 25.00 ml of tap water in each trial

The M of AgNo3 was 0.100

And the Volume of titrant in Ml was 22.20     22.28    21.81

[mike]

As Mitch always says, write the equation first

OK, so you have three titrant volumes 22.20, 22.28, and 21.81 which gives you an average titrant value of 22.10mL

Now, n = c.v (n = number of moles, c = concentration, v = volume)

you know c and v so you can work out number of moles of AgNO₃

[enjoi]

Would that be the molarity of the chloride ion concentration?

[mike]

Not exactly.

First write the equation of the reaction between silver nitrate and chloride in your sample.

Once you know the ratio of Ag to Cl then you can work out the number of moles of Ag, hence the number of moles of Cl and hence the concentration of Cl in your sample.