A certain municipal water sample contains 46.1 mg SO42-/L and 30.6 mg Cl -/L. How many drops (1 drop = 0.05 mL) of 0.0010 M AgNO3 must be added to 1.00 L of this water to just produce a precipitate?
What will this precipitate be?
How do i start this question? please help
By looking up the solubility product of AgCl. It will help to know if Ag2SO4 has a Ksp or not.
To solve this question, we need to determine the number of drops of 0.0010 M AgNO3 solution required to produce a precipitate in 1.00 L of water.
First, we need to find out which ion will react with AgNO3 to form a precipitate. In this case, we have SO42- and Cl- ions present in the water sample. Comparing the solubility rules, we know that Ag+ ions can react with Cl- ions to form a silver chloride precipitate (AgCl).
To determine the number of drops of AgNO3 needed, we can follow these steps:
Step 1: Calculate the moles of Cl- ions in 1.00 L of water sample.
- To do this, convert the given concentration of Cl- ions (30.6 mg/L) to moles using the molar mass of Cl- (35.45 g/mol).
- Divide the mass in grams by the molar mass to find the moles:
Moles of Cl- = (30.6 mg/L) / (35.45 g/mol)
Step 2: Calculate the moles of Ag+ ions required to react with the moles of Cl- ions.
- Since AgNO3 is a 1:1 molar ratio with Ag+ ions and NO3- ions, the moles of Ag+ ions required will be equal to the moles of Cl- ions.
Step 3: Calculate the amount of AgNO3 solution needed in liters.
- Convert the concentration of AgNO3 (0.0010 M) to moles per liter.
- Divide the moles of Ag+ ions required by the concentration of AgNO3 to find the volume in liters:
Volume of AgNO3 solution = Moles of Ag+ ions / Concentration of AgNO3
Step 4: Convert the volume of AgNO3 solution to drops.
- Multiply the volume in liters by the conversion factor (1 drop = 0.05 mL) to find the number of drops:
Number of drops = Volume of AgNO3 solution (in L) * (1 drop / 0.05 mL)
Finally, we can determine the precipitate by knowing that silver chloride (AgCl) will be formed when Ag+ ions react with Cl- ions.
Using these steps, you can calculate the number of drops of AgNO3 solution needed and determine the resulting precipitate.