I am trying to complete a lab called Precipitation Titration of Cobalt Chloride. I've done the experiment and I got that if you combine 18.01mL of 0.1M NaOH with 10mL of CoCl2, the precipitate is forms. Now how do I calculate the concentration of the amount of NaOH I added? Please help.
You added how may mols NaOH? That's M x L = mols.
What final volume do you have. You added 18.01 mL and 10 mL so total volume is 28.01 mL. Convert that to L., then M = mols/L
To calculate the concentration of the NaOH solution, you can use the concept of stoichiometry and the volume and concentration of CoCl2 used in the reaction.
Here are the steps to calculate the concentration of NaOH:
Step 1: Write the balanced chemical equation for the reaction between NaOH and CoCl2.
CoCl2 + 2NaOH -> Co(OH)2 + 2NaCl
Step 2: Determine the number of moles of CoCl2 used. To do this, you need to use the concentration and volume of the CoCl2 solution.
Given:
Volume of CoCl2 solution = 10 mL = 0.01 L
Concentration of CoCl2 solution = 0.1 M
Number of moles of CoCl2 = concentration × volume
= 0.1 M × 0.01 L
= 0.001 moles
Step 3: Use the stoichiometry of the balanced equation to find the number of moles of NaOH reacted with CoCl2.
From the balanced equation, it is clear that 1 mole of CoCl2 reacts with 2 moles of NaOH.
Number of moles of NaOH = (2/1) × number of moles of CoCl2
= (2/1) × 0.001 moles
= 0.002 moles
Step 4: Calculate the concentration of NaOH by dividing the number of moles of NaOH by the volume used (18.01 mL = 0.01801 L).
Concentration of NaOH = number of moles of NaOH / volume of NaOH solution
= 0.002 moles / 0.01801 L
= 0.111 M
Hence, the concentration of the NaOH solution is 0.111 M.
To calculate the concentration of the NaOH solution, you can use the concept of stoichiometry.
First, you need to determine the number of moles of NaOH used in the reaction. This can be done using the equation:
moles of NaOH = concentration of NaOH × volume of NaOH used (in liters)
Given that the volume of NaOH used is 18.01 mL or 0.01801 L and the concentration is 0.1 M, the calculation becomes:
moles of NaOH = 0.1 M × 0.01801 L = 0.001801 moles of NaOH
Next, you need to use the balanced equation for the reaction to determine the stoichiometric ratio between NaOH and CoCl2. The balanced equation for the reaction can be written as:
2NaOH + CoCl2 → Co(OH)2 + 2NaCl
From the balanced equation, you can see that 2 moles of NaOH react with 1 mole of CoCl2.
Therefore, the moles of CoCl2 used in the reaction can be calculated as:
moles of CoCl2 = (moles of NaOH) / (stoichiometric ratio) = 0.001801 moles of NaOH / 2 = 0.0009005 moles of CoCl2
Finally, to find the concentration of the CoCl2 solution, you need to divide the moles of CoCl2 by the volume of CoCl2 used. In this case, the volume of CoCl2 used is 10 mL or 0.01 L.
concentration of CoCl2 = (moles of CoCl2) / (volume of CoCl2 used in liters)
= 0.0009005 moles of CoCl2 / 0.01 L
= 0.09005 M
Thus, the concentration of the CoCl2 solution is 0.09005 M.