At 50.0°C, K_w is 5.5 x 10^-14. Determine [OH^-] in pure water at this temperature.

• A. 1.0x10^-7 M
• B. 2.3x10^-7 M
• C. 2.8x10^-14 M
• D. 5.0x10^-15 M
• E. 3.0x10^-27 M

Answer: (B)