Experiment 1: Liquid-Vapor Transition - Boiling of Water

Objective: In this experiment, the students will gain an understanding of the boiling process in a substance and will learn how the temperature varies for a constant pressure process of a liquid progressing to a vapor. The students will also investigate the effects of mixing of the fluid on the time required for boiling.

Goals: After completing this experiments, the students will

• Plot the temperature of the system vs. time for the constant pressure process, visually noting the points when the liquid water began to boil, and when all the water appeared to be in liquid form. The boiling temperature will be compared to tabulated values.

• Compare the plots of temperature vs. time for two experimental runs to study experimental repeatability.

• Produce a report verbally describing the heating/boiling process which they visually observed.

• Be able to use the data acquisition equipment to perform a simple experiment, and subsequently analyze the data

• Demonstrate an understanding of the pressure and temperature sensors.

Preliminary Experimental Apparatus:

Equipment needed for each setup

(1) Rectangular vessel (with window with light

(2) Beaker

(3) Immersion heater

(4) 3 Thermistors/Thermocouples

(5) Pressure gage

(6) Piping

(7) Ice Bath

(8) Valves for water inlet and drain

(9) Funnel/container system for water supply.

(10) Data Acquisition/PC

Basic Experimental Procedure:

(1) Students fill vessel approximately 1/2 with water.

(2) Immersion heater turned on

(3) Water is heated and then boils. Students should watch the boiling process, noting times of significant events such as the start of boiling. Experiment continues through several minutes of boiling (to be determined).

(4) Students note volume of water condensed into beaker.

(5) Students empty vessel and repeat experiment to demonstrate experimental repeatability.