Answer:
Molarity Ni^2+ = 0.0566 M
Explanation:
Step 1: Data given
Mass of nickel(II) chloride = 2.57 grams
volume of an aqueous 38.0 mM solution of potassium carbonate = 350 mL =0.350 L
The molar mass of nickel (II) chloride = 129.6 g/mol
Step 2: The balanced equation
NiCl2(aq) + K2CO3(aq) → 2KCl(aq) + NiCO3(s)
The dissociation of nickel (II) chloride:
NiCl2 → Ni^2+ + 2Cl-
Step 3: Calculate moles NiCl2
Moles NiCl2 = mass NiCl2 / molar mass NiCl2
Moles NiCl2 = 2.57 grams / 129.6 g/mol
Moles NiCl2 = 0.0198 moles
For 1 mol NiCl2 we have 1 mol Ni^2+
For 0.0198 moles NiCl2 we have 0.0198 moles Nickel(II) cation
Step 4: Calculate molarity Ni^2+
Molarity Ni^2+ = moles / volume
Molarity Ni^2+ = 0.0198 moles / 0.350 L
Molarity Ni^2+ = 0.0566 M
