Calculate the concentration of chloride ions when 100.0 mL of 0.205 M sodium chloride is mixed with 250.0 mL of 0.150 M calcium chloride.
A) 0.955 M
B) 0.382 M
C) 0.273 M
D) M
E) none of these

Question

Calculate the concentration of chloride ions when 100.0 mL of 0.205 M sodium chloride is mixed with 250.0 mL of 0.150 M calcium chloride.
A) 0.955 M 
B) 0.382 M 
C) 0.273 M 
D) M 
E) none of these

Quizplus · Accepted Answer

First, calculate the moles of chloride ions in each solution:

Moles of chloride ions in sodium chloride solution = 0.205 M x 0.1 L = 0.0205 moles
Moles of chloride ions in calcium chloride solution = 0.150 M x 0.25 L x 2 = 0.075 moles (calcium chloride contains 2 chloride ions per formula unit)

Then, add the moles of chloride ions together:

Total moles of chloride ions = 0.0205 moles + 0.075 moles = 0.0955 moles

Finally, calculate the concentration of chloride ions in the final solution:

Concentration of chloride ions = moles of chloride ions / total volume of solution
= 0.0955 moles / (0.1 L + 0.25 L) = 0.273 M

Therefore, the correct answer is choice C.

Calculate the Concentration of Chloride Ions When 100