Question: How Can We Identify An Unknown Substance?

How do you identify a substance?

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..

What quantity can you use to identify an unknown substance?

You can identify an unknown substance by measuring its density and comparing your result to a list of known densities. Density = mass/volume. Assume that you have to identify an unknown metal. You can determine the mass of the metal on a scale.

How do you identify an unknown ionic compound?

flame testadd 5ml of water to the test tube.add a small amount of the compound to the test tube and let the solution dissolve.add 3 drops of universal detector to the solution and gently shake the test tube. observe the color of the solution.repeat steps 1-4 for until all substances have been used.

How do you find the conductivity of an unknown compound?

The easiest way to determine whether a compound can conduct a current is to identify its molecular structure or composition. Compounds with strong conductivity dissociate completely into charged atoms or molecules, or ions, when dissolved in water. These ions can move and carry a current effectively.

How can you identify a salt?

The name of a salt starts with the name of the cation (e.g., sodium or ammonium) followed by the name of the anion (e.g., chloride or acetate). Salts are often referred to only by the name of the cation (e.g., sodium salt or ammonium salt) or by the name of the anion (e.g., chloride salt or acetate salt).

How do you identify an unknown solution in chemistry?

Let’s take a moment to review these methods. In precipitation, you can add a chemical to a solution and observe what precipitate forms. Acid/base tests will tell you the pH of the substance and whether it is an acid, base or neutral substance. Flame tests are used to identify ions based on the color the flames emit.

How can you identify an unknown substance?

Identifying Unknown SubstancesAppearance – use a magnifying glass to describe the appearance of the powder.Texture – feel the substance by pinching some between your fingers.Smell – carefully – without inhaling any – smell the substance.More items…

What is the unknown substance?

The purpose of this experiment is to identify an unknown substance chosen from the attached list. The procedure you will use is to determine several of its physical properties and chemical reactions and compare these to samples of known substances.

How can you identify an unknown salt?

Students identify unknown chloride salts by (1) using a precipitation reaction to determine if the cation is a group 1 or group 2 metal, (2) performing a titration with silver nitrate to determine the formula mass of the salt, and (3) confirming the identity of the salt using a flame test.

How do you test if an unknown substance is ionic or covalent?

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).

How can you say that one substance is different from other?

You cannot use mass to tell one substance from another because two very different objects can have the same mass—a kilogram of feathers has the same mass as a kilogram of peanut butter, for example. Other properties, such as density, can be used to identify substances.

Why is it important to identify unknown substances?

Detecting known substances, and determining their quantity, is also important. … In manufacturing, it is important to detect any impurities in the product and to determine whether they are present in a significant amount. Analytical characterization is critical in pharmaceutical products, for instance.

How do you identify sodium?

The most common method of identification of Na+ is the flame test. Sodium imparts a brilliant, long lasting, yellow flame that masks colors from other ions. The test may be performed on a small sample of the unknown treated with concentrated HCl or a few drops of solution unknown treated with concentrated HCl.