Observe the solubility graphs for gaseous solutes. The graph on the left shows how the solubility of a gaseous solute is affected by changes in pressure. The graph on the right shows how the solubility of a gaseous solute is affected by changes in temperature.
According to the graphs, a gas becomes more soluble (solubility increases) in a liquid when
A.
both temperature and pressure are increased
B.
both temperature and pressure are decreased
C.
the temperature is increased and the pressure is decreased
D.
the temperature is decreased and the pressure is increased
C. the temperature is increased and the pressure is decreased
According to the solubility graphs for gaseous solutes, a gas becomes more soluble (solubility increases) in a liquid when the temperature is decreased and the pressure is increased. Therefore, the correct answer is D.
To determine the correct answer, we need to analyze the information presented in the graphs. The solubility of a gaseous solute is influenced by changes in pressure and temperature.
Looking at the graph on the left, which represents the effect of pressure on solubility, we can observe that as pressure increases, the solubility of the gas also increases. This demonstrates a direct relationship between pressure and solubility. Therefore, we can conclude that increasing pressure increases the solubility.
Now, let's examine the graph on the right, which represents the effect of temperature on solubility. In this graph, we can see that as temperature decreases, the solubility of the gas increases. This indicates an inverse relationship between temperature and solubility. Hence, decreasing temperature increases the solubility.
Considering both graphs, we need to find an answer choice that aligns with the observations from each graph.
Choice A: If we increase both temperature and pressure, we can see that it matches with the result of increased solubility observed in both graphs. Therefore, this choice is incorrect.
Choice B: Decreasing both temperature and pressure contradicts the observations from both graphs since it would result in increased solubility according to the graph for temperature and decreased solubility according to the graph for pressure. Thus, this choice is not valid.
Choice C: Increasing temperature and decreasing pressure aligns with the increase in solubility due to the temperature decrease according to the temperature graph, but it contradicts the increase in solubility with pressure increase according to the pressure graph. So, this choice is not correct.
Choice D: Decreasing temperature and increasing pressure matches the decrease in solubility due to temperature decrease according to the temperature graph and the increase in solubility with pressure increase according to the pressure graph. Hence, this choice is the correct answer.