Table of Contents
Where do you place test tubes?
A test tube, also known as a culture tube or sample tube, is a common piece of laboratory glassware consisting of a finger-like length of glass or clear plastic tubing, open at the top and closed at the bottom. Test tubes are usually placed in special-purpose racks.
Why should the test tube be rotated over the flame?
Keep rotating the tube in the flame as this ensures uniform heating. Continue to heat it until it softens.
What type of flame and in what part of the flame should glass tubing be softened?
Bending Glass Tubing Hold the tubing horizontally in the hottest part of the flame. This is the blue part of a gas flame or just above the top of the inner cone of an alcohol flame. Your goal is to heat the section of glass you want to bend, plus about a centimeter on either side of this point.
How does flaming the mouth of a test tube work?
Flaming the Mouth of the Test Tube: Passing the mouth of a tube through the flame of a Bunsen burner creates a convection current which forces air out of the tube. This prevents airborne contaminants from entering the tube.
How is the result of a flame test determined?
For example, copper(I) emits blue light during the flame test, while copper(II) emits green light. A metal salt consists of a component cation (the metal) and an anion. The anion can affect the result of the flame test.
Is there an alternative to the flame test?
An alternative to the flame test is the bead test or blister test, in which a bead of salt is coated with the sample and then heated in a Bunsen burner flame.
How does a bunsen burner flame test work?
Part One: Flame Tests (As an option, this could be a demo rather than a student activity) When solutions of metals are heated in a Bunsen burner flame, they give off characteristic colours.