Carbon dioxide in solution

Calcium bicarbonate requires excess carbon dioxide in solution to stabilise it the necessary concentration depends on the other constituents of the water and the temperature. 

Presence of carbon dioxide in solutions of the hydride in dimethyl or bis(2-methoxy-ethyl) ether can cause a violent decomposition on warming the residue from evaporation. Presence of aluminium chloride tends to increase the vigour of decomposition to explosion. Lithium tetrahydroaluminate may behave similarly, but is generally more stable. 

Danckwerts [16] showed, on the basis of the absorption of sulfur dioxide in water and of carbon dioxide in solution, that absorption increases by dissociation processes. 

Carbon dioxide in solution does not significantly bind to hydrogen ions or other metal ions. Thus it is possible to treat CO2 as a reactant composed of a single species in biochemical reactions, without introducing a binding polynomial or multiple ion-bound states for C02. However, C02 can be hydrolyzed to H2C03 via the reaction... 

Figure 4.7 Salting-out coefficient for carbon dioxide in solution of sodium chloride (open circles - low pressure data and filled circles - high pressure data).

Soluble 1 in 290 of water, 1 in 30 of ethanol, and 1 in 12 of acetone slightly soluble in chloroform and ether readily soluble in dilute ammonia solution and in solutions of alkali hydroxides and, with the evolution of carbon dioxide, in solutions of alkali bicarbonates and carbonates. 

If carbon dioxide is bubbled through the calcium hydroxide solution, the carbonate is precipitated at first but later it dissolves again with the formation of calcium bicarbonate solution. This solution varies in pH depending on the quantity of carbon dioxide in solution but the pH is generally about 7. It can be used as a deacidifying treatment when a high pH must be avoided. 

Metabolism also produces carbon dioxide. In solution this gas forms a weak acid. Large amounts of CO, are produced by cellular activity each day with the potential to upset acid-base balance, but under normal circumstanecs all of this CO, is excreted via the lungs, having been transported in the blood. Only when... 

Gas-sensing membrane electrodes use a gas-permeable membrane that allows measured species (as a dissolved gas) to pass through and be measured within the electrode. These probes are very selective and sensitive for gases such as ammonia and carbon dioxide. For carbon dioxide, the working electrode is usually a modified glass pH electrode covered in a teflon membrane. Carbon dioxide in solution forms carbonic acid which lowers the pH. 

Solubilization of respiratory carbon dioxide in solutions around the plant can mediate convective flows in several plants, including deepwater rice (Raskin and Kende, 1985), Carex (Kon-calova et al., 1988), and young mangrove plants (Curran et al., 1986). Raskin and Kende (1985) provided evidence that convective flow of oxygen in deepwater rice is driven by solubilization of... 

The same relationship also holds for other species. For example, when CO2 gas dissolves in water, it hydrolyzes (reacts with water) to a very small extent, forming some H2CO3 molecules in solution. It is rather difficult to determine the exact amount of H2CO3, and this problem is avoided by simply calling the total amount of carbon dioxide in solution either C02(aq) or H2C03(a ), exactly as the dissolved silica is called 8i02(a ) or 1148104(0 ). Then for the same reason as before, we find that... 

This value of pK assumes that all the carbon dioxide in solution is present as carbonic acid. 

Carbonic anhydrase is a zinc-based enzyme that catalyzes the conversion of carbon dioxide to carbonic acid. In an experiment to study its effect, it was found that the molar concentration of carbon dioxide in solution decreased from 220 mmol dm" to 56.0 mmol dm" in 1.22 x 10 s. What is the rate constant of the first-order reaction ... 

The pH of aqueous solutions is extremely important in determining the type of corrosion inhibitor that is most effective and most economical. Natural hard waters retain calcium compounds, including calcium carbonate (CaCOj) and calcium bicarbonate (CafHCOjfj), along with carbon dioxide, in solution. There is an equilibrium among these species, as shown by Equation (5.4). 

M.H. Oyevaar, H.J. Fontein, K.R. Westerterp, Equilibria of carbon dioxide in solutions of diethanolamine in aqueous ethylene glycol at 298 K. J. Chem. Eng. Data 34(4), 405-408... 

Most cryogenic liquids contain small but finite traces of dissolved impurities such as carbon dioxide, water and hydrocarbons. On exposure to atmospheric air, LNG, LPG and other liquid hydrocarbons at temperatures below 0 °C, may absorb oxygen, nitrogen and carbon dioxide in solution, and water in solution or as a particulate. 

---