In the analysis of a sample of drinking water, a rate of 25.00 mL of the water requires 16.04 mL of AgNO3 to 0.05647 M in order to achieve an end to the Mohr method. What is the concentration of chloride ions in the sample?
mols Cl = M AgNO3 x L AgNO3 = ?
Then M Cl^- = mols Cl^-/L H2O = ?
To determine the concentration of chloride ions in the sample, we need to use the information provided and apply the principles of stoichiometry and chemical reactions.
Given:
Volume of drinking water sample (Vw) = 25.00 mL
Volume of AgNO3 solution (Vs) = 16.04 mL
Concentration of AgNO3 solution (C AgNO3) = 0.05647 M
The equation for the reaction between AgNO3 and chloride ions (Cl-) is as follows:
AgNO3 + Cl- -> AgCl + NO3-
Based on the reaction equation, we can determine the stoichiometry:
1 mol of AgNO3 reacts with 1 mol of Cl-
Therefore, the ratio of volume to moles between AgNO3 and Cl- is 1:1.
To find the moles of AgNO3 used, we need to calculate it using the given concentration and volume of AgNO3:
moles AgNO3 = concentration x volume (in liters)
Converting the volume of AgNO3 in milliliters to liters:
Vs = 16.04 mL = 16.04/1000 L = 0.01604 L
Now, we can calculate the moles of AgNO3:
moles AgNO3 = 0.05647 M x 0.01604 L
Next, we determine the moles of chloride ions (Cl-), knowing that the stoichiometry is 1:1:
moles Cl- = moles AgNO3
Now, we have the moles of chloride ions (Cl-), but we need to find the concentration. To do this, we divide the moles by the volume of the drinking water sample (Vw) in liters:
concentration of Cl- = moles Cl- / Vw
Substituting the values:
concentration of Cl- = moles AgNO3 / Vw
Now you can calculate the concentration of chloride ions in the drinking water sample using the given values.