By using our site, you acknowledge that you have read and understand our Cookie Policy, Privacy Policy, and our Terms of Service. Thus, the carbonate ion is more unstable compared to bicarbonate. Your second equation is unbalanced. Thus, even though it can delocalise the charge over one more oxygen atom, it does not compensate for the extra unit of negative charge. Why carbonic acid ( p$\ce{Ka = 6.3}$ ) is not stable? What kind of overshoes can I use with a large touring SPD cycling shoe such as the Giro Rumble VR? C(=O)(O)[O-] Although the carbonate ion has 3 equivalent structures, compared to the the bicarbonate ion, which only has 2 equivalent ones, the charge density of the ion is twice that of the bicarbonate ion. In summary, the key difference between carbonate and bicarbonate is that the carbonate ion has -2 electrical charge whereas, the bicarbonate has -1 electrical charge. Values are meant to compare things together especially in terms of pka. With no pressure applied, the amount of carbonate in solution if very low. The carbon oxoanion resulting from the removal of a proton from carbonic acid. @user158657 Your first query can be answered very logically. Why is the bicarbonate ion ( p$\ce{Ka = 10.3}$ ) more stable than the carbonate ion ? The reason for it comes to what I assume is your question, which I will rephrase as such: I expect that second acidic proton to behave like a carboxylic acid because of it's structure but it appears to be much more basic than anticipated. Is a software open source if its source code is published by its copyright owner but cannot be used without a commercial license? site design / logo © 2020 Stack Exchange Inc; user contributions licensed under cc by-sa. That is, the carbonate ion has a highly polarisable electron cloud, which can be distorted by densely positively-charged species, such as the hydrogen ion, in this case. This is due to there being a smaller negative charge on the bicarbonate ion and there being still 2 equivalent resonance structures to spread out the negative charge. Sodium bicarbonate is an ionic compound with the stock name sodium hydrogen carbonate. You can't meaningfully compare neutral molecules to ions in terms of stability. Ionic compounds are always electrically neutral because they have equal amounts of positive and negative charge. If the pH of blood increases, one would expect ____. This should be the correct line of thought. Carbonate ion = CO3 2- means carbonate is an anion with a negative 2 charges. In fact, the $\mathrm{pK_a}$ values themselves are telling you that the most stable species, Bicarbonate decomposition and pKa [closed], MAINTENANCE WARNING: Possible downtime early morning Dec 2/4/9 UTC (8:30PM…, “Question closed” notifications experiment results and graduation, Polarisation of electron clouds by partially positively-charged hydrogen atoms, Predicting pH of an acidic salt of an weak acid and weak base, Hydrolysis of salts containing amphiprotic anion, How to calculate pH of the Na2CO3 solution given ambiguous Ka values. What does commonwealth mean in US English? Bicarbonate could react in two ways in an aqueous solution: $[1]\qquad\ce{HCO3- + H2O -> CO3^2- + H3O+}$, $[2]\qquad\ce{HCO3- + H2O -> H2CO3 + OH-}$. Typically, the seven major ions (sodium, potassium, magnesium, calcium, bicarbonate, chloride, and sulfate) are enough to calculate a charge balance, but you need to know your system. How to limit population growth in a utopia? Limitations of Monte Carlo simulations in finance, What would result from not adding fat to pastry dough. Information about your device and internet connection, including your IP address, Browsing and search activity while using Verizon Media websites and apps. When you claim that one product is more stable, you need to mention in which condition otherwise we cannot make any prediction. What LEGO piece is this arc with ball joint? Since $\ce{H2CO3}$ is more stable than $\ce{CO3^2-}$ (because it has a lower charge and all the octets are completed), the p$K_{\mathrm a}$ must be high (more alkaline than acid). Structure, properties, spectra, suppliers and links for: Bicarbonate anion, hydrogencarbonate, 71-52-3. OOP implementation of Rock Paper Scissors game logic in Java. (Note: All Contain A Carbon- Nitrogen Bond) Which Molecule To You Expect To Have The Shortest Nitrogen-to-carbon Bond? "That is, the carbonate ion has a highly polarisable electron cloud, which can be distorted by densely positively-charged species, such as the hydrogen ion, in this case." number of resonance structures). Reference: 1. CopyCopied, Validated by Experts, Validated by Users, Non-Validated, Removed by Users, Predicted data is generated using the ACD/Labs Percepta Platform - PhysChem Module, Predicted data is generated using the US Environmental Protection Agency’s EPISuite™, Click to predict properties on the Chemicalize site, For medical information relating to Covid-19, please consult the, ACD/Labs Percepta Platform - PhysChem Module, US Environmental Protection Agency’s EPISuite™, Compounds with the same molecular formula, Search Google for structures with same skeleton. Problem is that this system of resonance cannot stabilise two charges. The reason for this is same as the one given for the instability of aluminium carbonate, iron (III) carbonate etc. Is Elastigirl's body shape her natural shape, or did she choose it? Thus, the position of the 2nd equilibrium mentioned in the question should be to the left, favouring the more stable species. Therefore, the position of equilibrium in the first reaction mentioned in the question should be to the left, not to the right. Thus, carbonic acid is not a very stable species and compared to the bicarbonate ion, which only has one densely-charged hydrogen ion distorting its electron cloud, it is definitely more unstable. What is the best way to remove 100% of a software that is not yet installed? Want to improve this question? Another OH on an sp2 carbon is phenol, and funny enough phenol pka is 9.95. CopyCopied, InChI=1S/CH2O3/c2-1(3)4/h(H2,2,3,4)/p-1 The answer to that question is obviously resonance structure of the carboxylic acid that stabilises the negative charge. Why is R_t (or R_0) and not doubling time the go-to metric for measuring Covid expansion? Chemistry Stack Exchange is a question and answer site for scientists, academics, teachers, and students in the field of chemistry. Compared to the carbonate ion, which has twice the charge density but yet only 1 more resonance structure, the bicarbonate ion is more stable. For me you explained why CO3-2 is more unstable than HCO3-.Could you try explain to me again ?