Answer:
[Ca²⁺] = 0.068 M
Step-by-step explanation:
The concentration of the calcium ion will be equal to the amount of calcium in CaCl₂, divided by the total volume:
C = n/V
When CaCl₂ dissociates in water, one mole of calcium ion is produced for every mole of CaCl₂, so the molar ratio of CaCl₂ to Ca²⁺ is 1:1. The moles of Ca²⁺ are calculated as follows:
(0.18 mol/L)(30.00 mL) = 5.4 mmol CaCl₂ = 5.4 mmol Ca²⁺
The total volume is (50.00 mL + 30.00 mL) = 80.00 mL
Thus, the concentration of Ca²⁺ is:
C = n/V = (5.4 mmol)/(80.00 mL) = 0.068 M