Hello sir, your videos are very helpful, thank you sir. However, I feel like it would be much better for me if you'd go deeper into the little details, it's hard for me to know how you got some of the values in the calculations.
Hi! I'm a little confused on the fraction of Ca2+. I believe we started with 50ml of it, but during the calculation, you plug in (25-5)/25, unless you were talking about the fraction of EDTA added instead?
you are trying to find the fraction of excess metal that did not react with edta. To do this, you need to compare the amount of EDTA added so far to the total amount needed to reach the equivalence point (25 mL). So 5 ml of EDTA was added out of the 25 needed. 20 mL of EDTA is needed to reach the equivalence point. So 20/25 is the fraction you need.
Hello, before the equivalence point we don't need to worry about using Kf because the amount of Ca2+ that is left only depends on how much has reacted with the EDTA. This doesn't involve an equilibrium - we just assume that all of the EDTA that is added completely reacts with the Ca2+ and the concentration of Ca2+ will be determined by what hasn't yet reacted.
Hello sir, your videos are very helpful, thank you sir. However, I feel like it would be much better for me if you'd go deeper into the little details, it's hard for me to know how you got some of the values in the calculations.
Hi! I'm a little confused on the fraction of Ca2+. I believe we started with 50ml of it, but during the calculation, you plug in (25-5)/25, unless you were talking about the fraction of EDTA added instead?
you are trying to find the fraction of excess metal that did not react with edta. To do this, you need to compare the amount of EDTA added so far to the total amount needed to reach the equivalence point (25 mL). So 5 ml of EDTA was added out of the 25 needed. 20 mL of EDTA is needed to reach the equivalence point. So 20/25 is the fraction you need.
why didn’t we use the Kf value ?
Hello, before the equivalence point we don't need to worry about using Kf because the amount of Ca2+ that is left only depends on how much has reacted with the EDTA. This doesn't involve an equilibrium - we just assume that all of the EDTA that is added completely reacts with the Ca2+ and the concentration of Ca2+ will be determined by what hasn't yet reacted.
Excuse me I did your calculation and am not getting 0.0291 M
you did it wrong then
aye bro next time just do it with mmol idk what the hell that calculation was