What is the pH of natural rain water? pH of natural rain water is determined by acidic and basic species that are CO2(8)+H20=H2CO3 naturally present in the TH2CO3 Unit: M atmosphere K ICOL,OI Equilibrium IH,CO3 constant Kell,oi CO2 partial pressure 1015=H2CO in unit of atm 370x10 C02: 370 ppm [H2CO3]=10-MWhat is the pH of natural rain water? H CO M x H CO p H CO K H O CO H O H CO K CO g H O H CO CO eq eq 4.9 2 3 6 1.5 2 3 2 3 2 2 2 2 3 2 2 2 3 [ ] 10 370 10 [ ] 10 [ ] [ ] [ ][ ] [ ] ( ) 2 − − − = = = = + = pH of natural rain water is determined by acidic and basic species that are naturally present in the atmosphere. Equilibrium constant CO2 partial pressure in unit of atm Unit: M CO2: 370 ppm