Question

In: Chemistry

Uncertainty calculation  I want to determine the air density (ρ, in kg/m3) using the following...


Uncertainty calculation  I want to determine the air density (ρ, in kg/m3) using the following equation.
p=(1/R)*(P/T)

where
P : barometric pressure, in Pa
T: temperature, in K
R: specific gas constant for dry air, 289.7 J/(kg·K) [assume constant has no uncertainty]

 I performed a sample-to-sample experiment with 6 repetitions/samples (n = 6). I got following results:
P = 96,389 ± 167 Pa
T = 311.8 ± 2.93 K

 The tags on the sensors show the barometric pressure sensor was factory calibrated at ±2% of the actual reading, and the temperature sensor was factory calibrated at ±2 K constantly.



QUESTION: Estimate the air density, ρ, and its uncertainty. You need to show the procedures of your calculations. Consider two tails 95% CI t-distribution.

Hints:
t value =2.571 (6 samples, 95% CI)
??/?? = 1/?∙?

  

??/?? = 1/?∙?^2

Solutions

Expert Solution


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