Indicate how accurate this measurement would be, and how many significant figure
ID: 534279 • Letter: I
Question
Indicate how accurate this measurement would be, and how many significant figures you could expect in your measurement. Temperature measurements Obtain a "special' thermometer from the instructor. Provide a method by which you could use this thermometer to measure some unknown temperature between room temperature (22°C) and 80°C. Indicate how accurate this measurement would be and how many significant figures you could expect in your measurement. You may assume that you have materials which you might commonly find in a laboratory such as hot plates, rulers, graph paper, ice cubes, beakers, etc.)Explanation / Answer
To measure an unknown temperature ,by using a thermometer with no scale, we have to calibrate the thermometer.
First of all, we have to determine the upper and lower fixed points.
Upper Fixed Point:
The bulb of the thermometer is immersed into a container containing boling water. The temperature starts rising and at a point the mercury column becomes stable. Mark that point as the upper fixed point.
Lower Fixed Point:
The bulb of the thermometer is immersed into a container containing ice. Therefore, the lower fixed point is identified and marked.
We know that freezing and boling points of water are 0 degree C and 100 degrees C respectively. Therefore, we have to divide the distance between upper and lower fixed points into 100 divisions.
Next, we have to immerse the bulb of the thermometer into a container containing water at room temperature (X). Therefore,
X = [ ( lx - l0) / ( l100 - l0 ) ] x 100
X can be calculated from the above equation.
Here, lx = length of the mercury column at X degrees C
l0 = length of the mercury column at 0 degree C
l100 = length of the mercury column at 100 degrees C
This measurement would be quite accurate. Accuracy would be measured by using a calibrated reference thermometer.
Given temparature 80 degrees C has one significant figure. For this reason, the expected significant figures = 1.