Question

What is the pH for a neutral solution at the body temperature $\left(38{}^{\circ }C\right)$ ?

• A. 7.2
• B. 14.0
• C. 6.8
• D. 6.0

Answer 1

Answer: (C)

With the rise in temperature, the ionic-product of water increases, hence $p{K}_{\omega }$ decreases $\left(p{K}_{\omega }=\log \frac{1}{K_{\omega }}\right)$ . We know that, $pH+pOH=p{K}_w$ Hence, pH of solution also decreases with increase in temperature. Hence, at body temperature $\left(38{}^{\circ }C\right)$ the pH of neutral solution will be approximately 6.8.