demonstration of exothermic and endothermic reactions

Mireille Tannous

10 Jan 201806:25

Summary

TLDRThis video script details two distinct chemical reactions: an endothermic and an exothermic process. In the endothermic demonstration, barium hydroxide and ammonium chloride are combined, causing a rapid temperature drop that freezes water, turning it into ice and sticking a piece of wood to a beaker. The exothermic reaction involves calcium carbonate reacting with concentrated sulfuric acid, producing heat and gas, visibly warming the beaker. These experiments vividly illustrate the heat absorption and release in chemical reactions.

Takeaways

🔬 The script describes two chemical experiments to demonstrate exothermic and endothermic reactions.
🧪 The first experiment involves a mixture of barium hydroxide and ammonium chloride, which is an endothermic reaction.
🌡️ A temperature sensor is used to record the temperature changes during the reactions.
❄️ The endothermic reaction causes the temperature to drop, turning water into ice due to heat absorption.
📉 The initial temperature of the barium hydroxide solution is around 24 degrees Celsius before the reaction.
📈 The second experiment uses calcium carbonate and concentrated sulfuric acid, which is an exothermic reaction.
🔥 The exothermic reaction generates heat, increasing the temperature and producing gas bubbles.
📌 The initial temperature of the second experiment is 22 degrees Celsius.
🧊 The wooden piece is used to demonstrate the extent of the temperature drop in the endothermic reaction by freezing the water between the beaker and the wood.
🔍 The script emphasizes the observable changes in the state of matter and temperature as a result of the chemical reactions.
📝 The script provides a clear example of how chemical reactions can either absorb or release heat, affecting the surroundings.

Q & A

What are the two types of chemical reactions demonstrated in the script?
-The script demonstrates exothermic and endothermic chemical reactions.
What substances are mixed in the endothermic reaction experiment?
-In the endothermic reaction experiment, barium hydroxide and ammonium chloride are mixed.
What method is used to measure temperature changes in the experiments?
-A temperature sensor is used to record the temperature changes during the chemical reactions.
Why does the experimenter wet a piece of wood before the endothermic reaction?
-The wood is wetted to observe the effect of the endothermic reaction on the water, which is expected to freeze due to heat absorption.
What is the initial temperature recorded before starting the endothermic reaction?
-The initial temperature recorded before the endothermic reaction is around 24 degrees Celsius.
What happens to the water between the beaker and the piece of wood during the endothermic reaction?
-The water between the beaker and the piece of wood freezes due to the heat absorption of the endothermic reaction.
What is the second experiment meant to demonstrate?
-The second experiment is meant to demonstrate an exothermic chemical reaction.
Which substances are used in the exothermic reaction experiment?
-Calcium carbonate and concentrated sulfuric acid are used in the exothermic reaction experiment.
What is observed during the exothermic reaction involving calcium carbonate and sulfuric acid?
-During the exothermic reaction, bubbles of gas are formed, and the beaker turns hot, indicating an increase in temperature.
What is the initial temperature recorded before starting the exothermic reaction?
-The initial temperature recorded before the exothermic reaction is 22 degrees Celsius.
What is the significance of the exothermic reaction in the script?
-The exothermic reaction is significant as it demonstrates a chemical process that releases heat, causing an increase in temperature.