A solution of 220mL of 0.200M Koh is mixed with a solution of 120mL of 0.240M NiSO4.

1.Determine limiting reactant?
2.Calculate the mass of precipitate formed?
3.Calculate the molarity of all ions left in the solution?

See your post above.

To determine the limiting reactant, we need to compare the number of moles of each reactant.

1. Calculate the moles of KOH:
moles of KOH = volume of KOH (L) × molarity of KOH (mol/L)
moles of KOH = 0.220 L × 0.200 mol/L

Similarly, calculate the moles of NiSO4:
moles of NiSO4 = volume of NiSO4 (L) × molarity of NiSO4 (mol/L)
moles of NiSO4 = 0.120 L × 0.240 mol/L

The limiting reactant is the one that produces fewer moles of product. So, compare the moles of product that can be produced from each reactant based on the balanced equation. Let's assume the balanced equation is:
KOH + NiSO4 -> Ni(OH)2 + K2SO4

In this case, 1 mole of KOH reacts with 1 mole of NiSO4 to produce 1 mole of Ni(OH)2. Therefore, the moles of product that can be produced from KOH and NiSO4 are equal to the number of moles of KOH and NiSO4, respectively.

Since the moles of KOH (0.220 × 0.200 = 0.044 mol) are lesser than the moles of NiSO4 (0.120 × 0.240 = 0.0288 mol), KOH is the limiting reactant.

2. To calculate the mass of precipitate formed (Ni(OH)2), we need to know the molar mass of Ni(OH)2. Let's assume it is M g/mol.

mass of precipitate (Ni(OH)2) = moles of limiting reactant (KOH) × molar mass of Ni(OH)2 (g/mol)
mass of precipitate = 0.044 mol × M g/mol

3. To calculate the molarity of all ions left in the solution, we need to know the total volume of the solution after mixing, as some of the ions may form solid precipitates.

Since the sum of the initial volumes is 220 mL + 120 mL = 340 mL, convert it to liters:
volume of the solution = 340 mL × 1 L/1000 mL

Now, we can calculate the molarity of each ion left in the solution. The balanced equation tells us that 1 mole of KOH produces 1 mole of K+ ions and 1 mole of OH- ions, while 1 mole of NiSO4 produces 1 mole of Ni2+ ions and 1 mole of SO4 2- ions.

Molarity of K+ ions = moles of K+ ions / volume of the solution (L)
Molarity of OH- ions = moles of OH- ions / volume of the solution (L)
Molarity of Ni2+ ions = moles of Ni2+ ions / volume of the solution (L)
Molarity of SO4 2- ions = moles of SO4 2- ions / volume of the solution (L)

The moles of each ion can be determined from the balanced equation and the moles of the limiting reactant (KOH).