What is the concentration of chloride ion when 75ml of 4.50m NaCl is mixed with 125mL of 1.42M FeCl3?
To determine the concentration of chloride ions in the mixture, we need to consider the amount of chloride ions contributed by each compound. In this case, we have NaCl and FeCl3.
First, we'll calculate the amount of chloride ions contributed by NaCl:
- The volume of 4.50 M NaCl is 75 mL, which can be converted to liters by dividing by 1000: 75 mL / 1000 mL/L = 0.075 L.
- The concentration of chloride ions in NaCl is equal to the molarity of NaCl because NaCl completely dissociates into Na+ and Cl- ions. Therefore, the concentration of chloride ions in NaCl is also 4.50 M.
- To calculate the amount of chloride ions contributed by NaCl, we multiply the volume (in liters) by the concentration: 0.075 L * 4.50 M = 0.3375 moles.
Next, we'll calculate the amount of chloride ions contributed by FeCl3:
- The volume of 1.42 M FeCl3 is 125 mL, which can be converted to liters: 125 mL / 1000 mL/L = 0.125 L.
- However, FeCl3 dissociates into one Fe3+ ion and three Cl- ions. So, for every mole of FeCl3, we have three moles of chloride ions.
- To find the moles of chloride ions contributed by FeCl3, we multiply the volume (in liters) by the concentration: 0.125 L * 1.42 M = 0.1775 moles FeCl3. Multiplying this by three, we get 0.5325 moles of chloride ions.
Now, we sum up the amount of chloride ions contributed by NaCl and FeCl3:
0.3375 moles (from NaCl) + 0.5325 moles (from FeCl3) = 0.87 moles.
Next, we calculate the total volume of the mixture:
75 mL (from NaCl) + 125 mL (from FeCl3) = 200 mL, which can be converted to liters: 200 mL / 1000 mL/L = 0.2 L.
Finally, we calculate the concentration of chloride ions in the mixture by dividing the total number of moles of chloride ions by the total volume of the mixture:
Concentration of chloride ions = 0.87 moles / 0.2 L = 4.35 M.
Therefore, the concentration of chloride ions in the mixture is 4.35 M.