The molecule that is nonpolar is CO2
Hard water<span>... is </span>water<span> that contains an appreciable quantity of dissolved minerals (like calcium and magnesium). </span>Soft water<span>... is treated </span>water<span> in which the only ion is sodium. As rainwater falls, it is naturally </span>soft<span>. </span>
It is achievable for the same enzyme to catalyze reverse reactions for the reason that the direction of a reversible reaction is determined by the concentrations of reactants and products. In pulmonary circulation, the low CO2 concentration supports the making of CO2 and H2O.