pOH of water is 7.0 at 298 K. If water is heated to 350 K, which of the following should be true ?

Question

pOH of water is 7.0 at 298 K. If water is heated to 350 K, which of the following should be true ? (A) pOH will decrease (B) pOH will increase (C) pOH will remain seven (D) Concentration of H+ ions will increase butthat of OH- will decrease

Tardigrade Admin · Accepted Answer

At 298 K, for pure water pH = pOH = 7. On increasing the temperature, the self ionisation of water increases thereby increasing the concentrations of H3O+ as well as OH- ions. Consequently, at high temperature, the pH as well as pOH will be < 7

Q. pOH of water is 7.0 at 298 K. If water is heated to 350 K, which of the following should be true ?

pOH will decrease

pOH will increase

pOH will remain seven

Concentration of $H^{+}$ ions will increase butthat of $O H^{-}$ will decrease

At $298 K$ , for pure water $p H = pO H = 7$ . On increasing the temperature, the self ionisation of water increases thereby increasing the concentrations of $H_{3} O^{+}$ as well as $O H^{-}$ ions. Consequently, at high temperature, the $p H$ as well as $pO H$ will be $< 7$