At a constant temperature, the Henry's law constants ( K_H ) for...

According to Henry's law, $p = K_H x$, where $p$ is the partial pressure of the gas, $K_H$ is the Henry's law constant, and $x$ is the mole fraction of the gas in the solution (solubility).

At a constant partial pressure, $x = \dfrac{p}{K_H}$. Thus, solubility is inversely proportional to the Henry's law constant ($K_H$).

The given $K_H$ values are:
$K_H(W) = 35 \text{ kbar}$
$K_H(X) = 0.15 \text{ kbar}$
$K_H(Y) = 76 \text{ kbar}$
$K_H(Z) = 1.67 \text{ kbar}$

The decreasing order of $K_H$ values is $Y > W > Z > X$.

Therefore, the increasing order of solubility is $Y < W < Z < X$.

Answer: $Y < W < Z < X$