@Karsten Theis : He mentioned water in equilibrium with the aerial CO2, therefore CaCO3 dissolution with CO2 support, forming carbonate hardness Ca(HCO3)2

Thanks for the comment. It is interesting it could be hard to read,but perhaps I am too used to ASCII based Usenet of the old days of the Internet. I will try to improve it.

Yes, this was a thoughtful remark.

Another factor is geometry, especially for larger molecules. Longer linear molecules have better van der Waals intermolecular bonding, while branched ones rather "decrease their surface" for such bonding.

My official Android client says at 2 places "Undefined control sequence \pu" (While otherwise displaying chemical formatting correctly)

I prefer dropping a camera from the canoe, but it is indecisive, as cameras are seldom a stainless steel cases these days. Sometimes it is hard to imagine one does not know the answer yet, where one reaches a stack exchange site. BTW, I do like your comments, seen in various topics.

I think downvoting without a comment or an edit suggestion is not much constructive. Note that the equilibrium concentration of Ca+2 and HCO3- is much higher than the other responder noted,, as CO2 presence shifts the dissolution equilibrium.