Table of Contents
- 1 How do you determine if a substance is an ionic compound?
- 2 How do you identify an unknown ionic compound?
- 3 How do you distinguish between ionic and covalent compounds?
- 4 How do you identify an unknown chemical?
- 5 How is crystal structure used to identify a substance?
- 6 What kind of substance is ionic with no melting?
How do you determine if a substance is an ionic compound?
A compound that contains ions and is held together by ionic bonds is called an ionic compound. The periodic table can help us recognize many of the compounds that are ionic: When a metal is combined with one or more nonmetals, the compound is usually ionic.
How do you identify an unknown ionic compound?
method
- set up Bunsen burner carefully.
- turn on gas and light the Bunsen burner carefully.
- turn the flame on to the heating flame.
- take a small amount of the compound on to the spatula.
- put the spatula with the compound in to the flame.
- observe the flame color produced by the compound.
How do you identify an unknown substance?
- Where might you come into contact with unknown chemicals in the real world?
- Simple tests you can do.
- Chromatographic methods.
- Spectroscopic methods.
- X-ray crystallography (a.k.a. X-ray diffraction, or XRD)
- Mass spectrometry (a.k.a. mass spec or MS)
How do you distinguish between ionic and covalent compounds?
A basic definition of an ionic compound is that they are molecules that consist of charged ions. These ions have opposite (both negative and positive) charges. On the other hand, covalent compounds are non-metals which are bound together, and consist of two electrons that are shared between two atoms.
How do you identify an unknown chemical?
Identifying Unknown Substances
- Smell: Most chemists can identify solvents by their distinctive smells (though this is a pretty bad idea). ¹
- Melting point: If you’ve got very pure crystals, you can use their melting point to figure out which of several possible chemicals you’ve got.
How do we identify substances?
Typically, the identity of a substance can be described by a:
- chemical name, for example, benzene;
- number, for example, EC number 200-753-7, and.
- chemical composition, for example, >99 % benzene and <1 % toluene. The composition is determined by chemical analysis.
First, a sample of the unknown substance can be placed in a test tube and put over a flame. This is done to determine the melting point. If the substance melts, then it is probably a covalent simple molecular substance (as shown in the table). However, if no melting occurs, the substance can either be ionic, covalent giant atomic, or metallic.
How is crystal structure used to identify a substance?
It’s usually not used to identify an unknown substance, but to figure out the long-range structures of known materials. If you have a protein and want to know how it folds, or if you want to know what the structure of a crystal is, this will do the job. It requires that the sample be crystalline.
What kind of substance is ionic with no melting?
If the substance melts, then it is probably a covalent simple molecular substance (as shown in the table). However, if no melting occurs, the substance can either be ionic, covalent giant atomic, or metallic.
Can a compound contain both metals and nonmetals?
No. Not always. But there is a rule of thumb that makes it easy to recognize many compounds as ionic. Compounds that contain both metals and nonmetals are usually ionic. For example, Na2SO4 contains a metal (Na) and nonmetals (sulfur and oxygen), and so is expected to be ionic.