A gas in contact with a liquid shows the following behavior at constant temperature: when $P = 1\ \text{atm}$, $x = 0.02$, and when $P = 3\ \text{atm}$, $x = 0.06$. What is the best conclusion?

Principle: Henry's law requires $P = K_H x$, so for valid behavior the ratio $P/x$ should remain constant. 1. For the first data point, $K_H = P/x = 1/0.02 = 50\ \text{atm}$. 2. For the second data point, $K_H = 3/0.06 = 50\ \text{atm}$. 3. Since the same constant is obtained both times, the data fit Henry's law exactly. Why the distractors are wrong: A is tempting if one assumes any change in $P$ changes $K_H$, but at fixed temperature $K_H$ remains constant for a given system. C is unsupported because the proportionality is actually perfect. D is false because $x$ increases as $P$ increases.