[单选题]
A fixed mass of ideal gas is trapped in a closed container. The graph shows how two variables related to the gas vary.
The gradient of the graph is $kV$ while $k$ is constant and $V$ is the volume of the container.
In the table below, which row correctly describes quantities X and Y?
$\ \ \ \ \ X\ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ \ Y$
A. Temperature in Celsius;Pressure
B. Temperature in Kelvin;Pressure
C. Pressure;Temperature in Celsius
D. Pressure;Temperature in Kelvin
参考答案:
A
本题详细解析:
Explanation:
From the ideal gas law,
$pV=nRT$ therefore,
$T=\frac{V}{nR}P$
This equation would lead to a graph of $T$ vs $P$ that passes through the origin, however the given graph does not. This can be accounted for by a conversion from absolute temperature to celsius temperature through a shift of 273.
Alternatively:
A graph of pressure against temperature will give a straight line.
The vertical (X) axis has negative values. This means it must be temperature in Celsius, as neither pressure nor Kelvin temperature can have a negative value. Thus, the horizontal (Y) axis is pressure and the correct answer is A.
