A 25.00 mL solution of 0.150 M NaCl is mixed with 10.00 mL of a 0.0750 M CaCl2 solution. Assuming the total volume is 35.00 mL, calculate the concentration of chloride ions in the resulting solution.

Chemistry · High School · Thu Feb 04 2021

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 To calculate the concentration of chloride ions in the resulting solution, we can follow these steps:

Step 1: Calculate the moles of chloride ions from NaCl Since there are 25.00 mL of a 0.150 M NaCl solution, which implies there is a 1:1 ratio between NaCl and Cl⁻ ions, we calculate the moles of Cl⁻ ions from NaCl like so: Moles of Cl⁻ from NaCl = Molarity (M) of NaCl × Volume (L) of NaCl solution = 0.150 mol/L × 0.02500 L = 0.00375 moles

Step 2: Calculate the moles of chloride ions from CaCl2 Since 1 mole of CaCl2 yields 2 moles of Cl⁻ ions due to the 1:2 ratio, we calculate the moles of Cl⁻ ions from CaCl2 like so: Moles of Cl⁻ from CaCl2 = 2 × (Molarity (M) of CaCl2 × Volume (L) of CaCl2 solution) = 2 × (0.0750 mol/L × 0.01000 L) = 2 × 0.000750 moles = 0.001500 moles

Step 3: Calculate the total moles of chloride ions Total moles of Cl⁻ ions = Moles of Cl⁻ from NaCl + Moles of Cl⁻ from CaCl2 = 0.00375 moles + 0.001500 moles = 0.005250 moles

Step 4: Calculate the new concentration of chloride ions Concentration (C) = Total moles of Cl⁻ ions / Total volume of the mixture (L) = 0.005250 moles / 0.03500 L = 0.150 M

So, the concentration of chloride ions in the resulting solution is 0.150 M.