Answer:
1090 mmHg
Explanation:
We know that with gases we must use Kelvin temperatures, so let’s try a plot of pressure against the Kelvin temperature.
We can create a table as follows
t/°C T/K p/mmHg
10 283 726
20 293 750
40 313 800
70 343 880
100 373 960
150 423 ???
I plotted the data and got the graph in the figure below.
It appears that pressure is a linear function of the Kelvin temperature.
y = mx + b
where x is the slope and b is the y-intercept.
Calculate the slope
I will use the points (275, 700) and (380, 975).
Slope = Δy/Δx = (975 -700)/(380 – 275) = 275/105 = 2.619
So,
y = 2.619x + b
Calculate the intercept
When x = 275, y = 700.
700 = 2.619 × 275 + b
700 = 720 + b Subtract 720 from each side and transpose.
b = -20
So, the equation of the graph is
y = 2.619x -20
Calculate the pressure at 423 K (150°C)
y = 2.619 × 423 -20
y = 1110 -20
y = 1090
At 150 °C, the pressure 1090 mmHg.
The point is approximately at the position of the black dot in the graph.
