Introduction

In this experiment, we will examine microwave heating and will determine the factors that impact post-superheating nucleation, in which an event of sudden violent boiling occurs when a liquid is heated before its boiling point. We will be answering some related questions as hypotheses of this experiment like-

1. The shape of the container.

2. Presence of pores on its internal surface.

3. Presence of scratches on otherwise glossy internal surfaces.

4. Dissolving solutes like sugar, salt, and coffee into the water.

Aim

To determine the factors that impact post-superheating nucleation.

Theory

1. Superheating is sometimes called boiling delay and boiling retardation.

2. Superheating is a process in which a liquid is heated, without boiling, at a temperature higher than its boiling point.

3. In this process, boiling is induced by an internal or external process and can happen at any time.

4. Nucleation can be defined as the process that determines how much an observer should wait to observe a new phase.

Materials required

1. Microwave oven,

2. Tap water,

3. Distilled water,

4. Glass containers in three shapes; wall flaring upward, wall flaring downward, and straight walls,

5. Non-glossy container with small pores (styrofoam),

6. Salt,

7. Sugar,

8. Coffee,

9. Insulated gloves,

10. Stopwatch,

11. MIcrowave oven.

Procedure

Step 1: In a container, put 200 ml of liquid.

Step 2: Place this container inside a microwave oven and heat it for seven minutes.

Step 3: Record the time when the first heating occurs.

Step 4: Now, let the liquid boil until sudden nucleation and accompanying explosion occurs.

Step 5: Record this elapsed time.

Step 6: Using insulated gloves, carefully remove the container from the microwave.

Step 7: Repeat this experiment for every set of hypotheses discussed in this experiment, i.e., different shapes of the container, container surface, container material, and the addition of solute.

Observation

1. We have observed that the container that had an upward flaring wall had the longest time for post-superheating devotion. After this came the one that had a straight wall and a downward flaring wall.

2. Those containers that had pores on the inside surface had no post-superheating nucleation. Once the normal nucleation began, it continued.

3. Those containers that had scratches on the surface had a similar effect.

4. The salt solution also does not show post-superheating nucleation.

5. For the solution of coffee and sugar, the time to post-superheating nucleation was longer than that for the plain water.

Result

1. Containers with an upward flaring wall had a longer time for post-superheating nucleation, then came a straight wall and downward flaring wall.

2. Containers that had pores, scratches, and salt solution showed no post-superheating nucleation.

3. The time for the solution of coffee and sugar had post-superheating nucleation longer than the plain water.

Precautions

1. Do not touch the heated container with naked hands.

2. Container should not be too hard.

3. Gloves should be the insulator of heat.

Viva Questions and Answers

Q.1 What was the aim of your experiment?

ANS. To determine the factors that impact post-superheating nucleation.

Q.2 What do you understand about superheating?

ANS. Superheating is a process in which a liquid is heated, without boiling, at a temperature higher than its boiling point.

Q.3 What is the effect of a container that has an upward flaring wall on post-superheating nucleation?

ANS. Containers with an upward flaring wall had a longer time for post-superheating nucleation, then came a straight wall and downward flaring wall.

Q.4 What do you understand about nucleation?

ANS. Nucleation can be defined as the process that determines how much an observer should wait to observe a new phase.

Q.5 What is the effect of pores on post-superheating nucleation?

ANS. Those containers that had pores on the inside surface had no post-superheating nucleation.

Saquib Siddiqui

Saquib Siddiqui is a Mechanical Engineer and a content creator. He has special interest in science experiments and teaches the same to school and college students. He is also a technical lead at RUDE LABS PVT. LTD.