Some solid copper(II) sulfate is dissolved in sufficient water to make 100.0 mL of solution. Enough of a sodium hydroxide solution of concentration 0.1500 mol/L is added just to react with all of the first solution, with none left over. This turns out to be a volume of 47.08 mL. (a)calculate the mass of the solid copper(II) sulfate. (b)calculate the end concentrations of all dissolved ions.
Part a is a stoichiometry problem. Just follow the steps at this link.
http://www.jiskha.com/science/chemistry/stoichiometry.html
Part b.
The equation is
CuSO4 + 2NaOH ==> Cu(OH)2 + Na2SO4
Make an ICE chart. The equilibrium conditions will be moles/L. Don't forget that the final volume is 147.08 mL. Also, the (CU^+2) will be determined from the solubility product of Cu(OH)2.
Post your work if you get stuck.
To calculate the mass of the solid copper(II) sulfate, we need to use stoichiometry and the given volume of sodium hydroxide solution added.
Step 1: Write the balanced equation for the reaction between copper(II) sulfate and sodium hydroxide:
CuSO4 + 2NaOH -> Cu(OH)2 + Na2SO4
Step 2: Determine the molar ratio between copper(II) sulfate and sodium hydroxide from the balanced equation. In this case, for every 1 mole of copper(II) sulfate, 2 moles of NaOH are required.
Step 3: Calculate the number of moles of sodium hydroxide used:
Number of moles of NaOH = concentration of NaOH x volume of NaOH
= 0.1500 mol/L x 0.04708 L
= 0.007062 mol
Step 4: Since the molar ratio between copper(II) sulfate and sodium hydroxide is 1:2, we know that the number of moles of copper(II) sulfate used is half the number of moles of sodium hydroxide used:
Number of moles of CuSO4 = 0.007062 mol / 2
= 0.003531 mol
Step 5: Calculate the molar mass of copper(II) sulfate:
CuSO4 = (1 x 63.55 g/mol) + (1 x 32.07 g/mol) + (4 x 16.00 g/mol)
= 159.61 g/mol
Step 6: Calculate the mass of solid copper(II) sulfate:
Mass of CuSO4 = Number of moles of CuSO4 x molar mass of CuSO4
= 0.003531 mol x 159.61 g/mol
= 0.5639 g
Therefore, the mass of the solid copper(II) sulfate is approximately 0.5639 grams.
To calculate the end concentrations of all dissolved ions, we need to use the volume of the final solution and the concentration of the sodium hydroxide solution.
Step 1: Calculate the total volume of the final solution:
Volume of final solution = volume of copper(II) sulfate solution + volume of sodium hydroxide solution
= 100.0 mL + 47.08 mL
= 147.08 mL
Step 2: Convert the volume of the final solution to liters:
Volume of final solution = 147.08 mL x (1 L / 1000 mL)
= 0.14708 L
Step 3: Calculate the moles of sodium hydroxide used in the reaction:
Number of moles of NaOH = concentration of NaOH x volume of NaOH
= 0.1500 mol/L x 0.04708 L
= 0.007062 mol
Step 4: Calculate the concentration of sodium hydroxide in the final solution:
Concentration of NaOH = Number of moles of NaOH / Volume of final solution
= 0.007062 mol / 0.14708 L
= 0.04807 mol/L
Step 5: Calculate the concentration of copper(II) ions (Cu2+) in the final solution:
Since the molar ratio between CuSO4 and Cu2+ is 1:1, the concentration of Cu2+ is equal to the concentration of CuSO4, which is 0.04807 mol/L.
Step 6: Calculate the concentration of sulfate ions (SO4^2-) in the final solution:
Since the molar ratio between CuSO4 and SO4^2- is 1:1, the concentration of SO4^2- is equal to the concentration of CuSO4, which is 0.04807 mol/L.
Step 7: Calculate the concentration of sodium ions (Na+) in the final solution:
Since the molar ratio between NaOH and Na+ is 2:2, the concentration of Na+ is twice the concentration of NaOH, which is 2 x 0.04807 mol/L = 0.09614 mol/L.
Therefore, the end concentrations of all dissolved ions in the final solution are approximately:
Cu2+: 0.04807 mol/L
SO4^2-: 0.04807 mol/L
Na+: 0.09614 mol/L