109 section Pre-Laboratory Assignment 1. Suppose a student who was unprepared fo
ID: 548619 • Letter: 1
Question
109 section Pre-Laboratory Assignment 1. Suppose a student who was unprepared for this experiment neglected to open the pinch clamp on the flask assembly prior to heating the flask assembly in boiling water. Describe the problems this situation would create. 3. Explain why it is essential that the inside of the flask be absolutely dry before it is fitted with the stop- per assembly and weighed. 2. A student performed this experiment and col- lected the following data: volume of air at fhigh (100 C)-260 mL volume of air at tjow (24.0 C) 205 mL (1) Plot the volume on the ordinate and the tem- perature on the abscissa. Draw a line connecting the two points (2) Extrapolate the line to the point on the x-axis where V- 0, and determine the value of Y (3) Calculate the percent error between the value of Y found by this graphical procedure and the accepted value of-273 C.Explanation / Answer
1) You haven’t provided the experimental details. I do not know what experiment you performed. But given the question, I am assuming that the experiment deals with heating a liquid or a mixture of liquids in a boiling water bath. Based on this assumption, I shall answer the question.
When the flask with its content is introduced in a boiling water bath, the liquid inside will vaporize and produce gas. The gas produced exerts pressure on the flask and hence, the pinch clamp must be loosened or opened to release the gas pressure. Otherwise, the gas pressure will build up inside the flask and may lead to cracking or braking of the hot flask and its content, leading to a potential accident.
2) (1) The pairs of values are as below.
Temperature in °C
Volume of air (mL)
100
260
24
205
Plot the data as below. The volume of air is the ordinate (y-axis) while the temperature is the abscissa (x-axis).
Plot of volume of air vs temperature of air
(2) Use the linear regression equation to find the temperature of the gas where the volume of the gas is zero. Put y = 0 and obtain
0 = 0.7237x + 187.63
====> -0.7237x = 187.63
====> x = -187.63/0.7237 = -259.26
The experimental temperature where the volume of the gas is 0 mL is -259.26°C (ans).
(3) Percent error between the theoretical value of -273°C and the experimental error is -259.26°C = (-273°C) – (-259.26°C)/(-273°C)*100 = 5.03296% 5.03% (ans).
Temperature in °C
Volume of air (mL)
100
260
24
205
Related Questions
Navigate
Integrity-first tutoring: explanations and feedback only — we do not complete graded work. Learn more.