Supporting and Heating Glassware

Try these questions

5 questions from this lesson’s quiz. Start the lesson to answer them and see the right answers.

1. 1. Why must a beaker be placed on a wire gauze with a ceramic centre when it is heated over a Bunsen burner flame?

   • A. To spread heat evenly and prevent thermal shock and cracking
   • B. To make the Bunsen flame luminous
   • C. To concentrate all the heat in one small hot spot
   • D. To stop the beaker from absorbing water

2. 2. Wanjiru is heating a liquid in a test tube using a wooden holder. How should she position the tube?

   • A. Upright, with the mouth pointing towards her face
   • B. Tilted at about 45 degrees, with the mouth pointing away from everyone
   • C. Horizontal, with the mouth pointing towards her partner
   • D. Upright, with the tube held in the hottest part of the flame and not moved

3. 3. A test tube is being heated safely using the one-third rule. The tube can hold 24 ml of liquid when full. What is the greatest volume of liquid, in ml, that should be put in it?

   Type your answer (in ml) in the lesson.

4. 4. Water in a beaker is heated from below. What causes a convection current to form?

   • A. Cold water at the bottom expands and rises
   • B. Warm water expands, becomes less dense and rises while cooler, denser water sinks
   • C. The glass beaker pushes the water upwards
   • D. Water particles stop moving at the top of the beaker

5. 5. What name is given to the heat transfer in liquids and gases caused by the movement of warm, less dense fluid rising and cooler, denser fluid sinking?

   Type your answer in the lesson.

More in Laboratory Apparatus & Instruments

• ▸Safe Chemical Handling
• ▸Laboratory Safety Showcase
• ▸Introduction to Laboratory Apparatus and Safety
• ▸Heating Apparatus The Bunsen Burner
• ▸Apparatus for Measuring Temperature
• ▸Measuring Length and Area
• ▸Measuring Mass and Weight in the Laboratory
• ▸Measuring Liquid Volume

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