Gas Collection Techniques Using Water Displacement Method

The video tutorial demonstrates how to collect gas using the water displacement method, suitable for gases insoluble in water. It explains the use of a measuring cylinder to record gas volume and provides an alternative method using a smaller tray. An example reaction between hydrochloric acid and magnesium is shown to illustrate the gas collection process.

What is the primary condition for using the water displacement method for gas collection?

• The gas must be heavier than air.

• The gas must be soluble in water.

• The gas must be lighter than air.

• The gas must be insoluble in water.

Why might a measuring cylinder be preferred over a gas tube in this method?

• It is more durable.

• It is less expensive.

• It allows for the measurement of gas volume.

• It is easier to handle.

What is the purpose of keeping the tip of the measuring cylinder upwards while lowering it into the water?

• To allow the cylinder to fill with water and eliminate air.

• To prevent water from entering.

• To ensure air is trapped inside.

• To make it easier to handle.

What should you be cautious about when lifting the measuring cylinder after inverting it?

• Lifting it without a clamp.

• Lifting it above the water surface.

• Lifting it too quickly.

• Lifting it with too much force.

In the alternative method, how is the measuring cylinder sealed before submerging it?

• With a piece of cloth.

• With a rubber stopper.

• With a hand or thumb.

• With a plastic cap.

What reaction is used as an example for gas collection in the demonstration?

• Zinc and sulfuric acid.

• Sodium and water.

• Hydrochloric acid and magnesium ribbon.

• Vinegar and baking soda.

What is the role of the delivery tube in the gas collection setup?

• To measure the gas volume.

• To transport gas from the reaction to the measuring cylinder.

• To prevent gas from escaping.

• To mix the reactants.

What observation indicates that gas is being collected in the measuring cylinder?

• Bubbles are produced and gas accumulates at the top.

• The water becomes cloudy.

• The cylinder changes color.

• The water level rises.

How can the volume of gas collected be determined in this method?

• By weighing the cylinder.

• By measuring the water displacement.

• By reading the scale on the measuring cylinder.

• By timing the reaction.