(c) If pH of solution increased from 3 to 6,H+ion concentration will be reduced to 1000 times. pH=−log[H+] [H+]‌when‌pH=3, 3=−log[H+] antilog (−3)=[H+] ........(i) 10−3=[H+]........(i) Also, [H+]‌when‌pH=6, 6=−log[H+] antilog (−6)=[H+] 10−6=[H+].......(ii).....(ii) From (i) and (ii), it can be seen if pH is increased from 3 to 6,H+concentration will be reduced by 1000 times.