Question 2: Use your balanced equation to calculate the volume of 0.12 M Na3PO4 to stoichiometrically react with the 3.0 mL of Co (NO3)2. Show your work.
3) Discuss how your supernatant color in the 6 different test tubes supports your calculated result in #2. For example, if you used less than the volume of sodium phosphate calculated in #2, what would be the limiting reactant and does the observed supernatant color support this.
Why is the supernatant important when determining the limiting regents. ALSO would I use molarity to solving question 2?
4 answers
See your previous post. I'm overwhelmed!
Those are the instructions but I just need help with this question. I balanced the reaction between cobalt ii nitrate with sodium phosphate. And I wanted to know why they supernatant liquid color was important when I mixed these two solutions together. I observed a purple color solid when the reaction occurred and the supernatant was red/pink.
From what I can gather from that long string of instructions the idea is to determine the solubility of Co3(PO4)2. I believe the idea is that Co(NO3)2 is colored. So when it reacts with the Na3PO4 it ppts the Co ion as the phosphate (solid) and settles (or is centrifuged) to the bottom. If ALL of the Co ion has reacted the supernatant liquid will be colorless; if there is still some Co ion not yet ppted it will be colored. The more Co ion that is un-precipitated the more intensely colored the supernatant liquid will be.
In many cases one can use molarity to determine limiting reagent but in some cases no; therefore I always go with mols to determine the limiting reagent. If you have M and volume, then mol = M x L. When working with small quantities like this I often use millimols. mmols = mL x M and when it comes time to convert back to M the easy way is M = mmols/mL.
In many cases one can use molarity to determine limiting reagent but in some cases no; therefore I always go with mols to determine the limiting reagent. If you have M and volume, then mol = M x L. When working with small quantities like this I often use millimols. mmols = mL x M and when it comes time to convert back to M the easy way is M = mmols/mL.
Where Co(NO3)_2 is the limiting reagent the mmoles of the precipitate will be related to the mmoles of Co(NO3)_2 originally present by the balanced stoich. and the filtrate will be colorless?
And if Na_3PO_4 is the limiting reagent the filtrate will be red/pink?
This is my balanced eq.
3Co(NO3)_2(aq) + 2Na_3PO_4(aq) ==> CO_3(PO_4)_2(s)+6NaNO_3(aq)
_ =subscript
And if Na_3PO_4 is the limiting reagent the filtrate will be red/pink?
This is my balanced eq.
3Co(NO3)_2(aq) + 2Na_3PO_4(aq) ==> CO_3(PO_4)_2(s)+6NaNO_3(aq)
_ =subscript