5 Minutes = MARKS: Electrolysis of water- Class 10- Science🔥

Summary

This video explains the process of water electrolysis and its decomposition into hydrogen and oxygen gases. It details the setup, including the use of plastic mugs, water, graphite rods, and a battery to pass electricity through the water. The video further explains how the positive terminal (anode) and negative terminal (cathode) of the setup interact with the water, producing oxygen at the anode and hydrogen at the cathode. The differences in gas volumes and their reactions with fire are also discussed, showing how oxygen supports combustion and hydrogen creates a popping sound when ignited.

Takeaways

• 😀 The process of electrolysis of water involves passing electricity through water to break it down into hydrogen and oxygen gases.
• 😀 The setup for this experiment includes a plastic mug filled with water, graphite rods, and a battery to provide electricity.
• 😀 The two rods in the setup are connected to the positive and negative terminals of the battery, with the positive rod called the anode and the negative rod called the cathode.
• 😀 Positive ions (cations) move towards the cathode, while negative ions (anions) move towards the anode during electrolysis.
• 😀 Oxygen gas collects in the test tube connected to the anode, while hydrogen gas collects in the test tube connected to the cathode.
• 😀 Hydrogen gas is present in double the quantity compared to oxygen gas because water (H2O) contains two hydrogen atoms for every oxygen atom.
• 😀 The volume of hydrogen gas produced is greater than oxygen due to the higher proportion of hydrogen atoms in water molecules.
• 😀 When a burning candle is brought near the oxygen-filled test tube, the flame intensifies because oxygen supports combustion.
• 😀 Conversely, when a burning candle is brought near the hydrogen-filled test tube, it makes a popping sound as hydrogen does not support combustion as effectively as oxygen.
• 😀 Hydrogen is a saturated compound, whereas oxygen is unsaturated, leading to different combustion characteristics when exposed to flames.
• 😀 Electrolytic decomposition of water, resulting in the production of hydrogen and oxygen gases, highlights the importance of electricity in breaking chemical bonds in compounds like water.

Q & A

What is electrolysis of water?

Electrolysis of water is a process where electrical energy is used to break down water (H2O) into hydrogen gas (H2) and oxygen gas (O2). This occurs when electricity is passed through water containing an electrolyte, like graphite rods, which allows conduction.

Why is graphite used as electrodes in this experiment?

Graphite rods are used as electrodes because they are good conductors of electricity and can withstand the electrical current without reacting, making them ideal for the electrolysis process.

What happens at the anode during electrolysis of water?

At the anode, which is connected to the positive terminal of the battery, oxygen gas is released. This is because the positive ions (cations) are attracted to the negative electrode, where they lose electrons and form oxygen.

What happens at the cathode during electrolysis of water?

At the cathode, which is connected to the negative terminal of the battery, hydrogen gas is released. This is because the negative ions (anions) are attracted to the positive electrode, where they gain electrons and form hydrogen.

Why is the volume of hydrogen gas double that of oxygen gas in this experiment?

The volume of hydrogen gas is double that of oxygen gas because water (H2O) consists of two hydrogen atoms for every one oxygen atom. Therefore, during the electrolysis process, twice as much hydrogen is produced compared to oxygen.

What happens when a burning candle is brought near the oxygen side of the electrolysis setup?

When a burning candle is brought near the oxygen side, the flame burns brighter and faster. This is because oxygen supports combustion and increases the rate of burning.

What happens when a burning candle is brought near the hydrogen side of the electrolysis setup?

When a burning candle is brought near the hydrogen side, it produces a 'pop' sound. This happens because hydrogen does not support combustion as strongly as oxygen, and it reacts differently when exposed to fire.

Why does the flame behave differently near the oxygen and hydrogen test tubes?

The flame behaves differently because oxygen is unsaturated and enhances combustion, making the flame larger and brighter. In contrast, hydrogen is saturated and does not support combustion as strongly, leading to a smaller flame and the characteristic 'pop' sound.

How can we differentiate between oxygen and hydrogen gas in this experiment?

Oxygen can be identified by bringing a burning candle near the test tube, where the flame intensifies. Hydrogen can be identified by the 'pop' sound when it reacts with the flame.

What role does the electrolyte play in the electrolysis of water?

The electrolyte is essential for the conduction of electricity through the water. It helps to ionize the water, making it possible for the electrical current to flow, which enables the water to decompose into hydrogen and oxygen gases.