Learning outcomes Introduction to Chemistry The Scopes of Chemistry Relation Between Chemistry and Other Branches of Science The Importance of Studying Chemistry The Process of Research in Chemistry Safety Measures in Chemistry Laboratory and in use of Chemicals Concepts of Chemistry Note Introduction to Chemistry What is chemistry? Chemistry is one of the branches of … Read more
Physical change All chemical substances consist of one or more elements. Sometimes, changes occur only in the physical conditions of a substance leaving its chemical structure unchanged. This is called a physical change. Physical change examples A solid piece of ice, if kept at room temperature, absorbs heat from the environment and gradually melts into … Read more
What do you mean by alloy? An alloy is a substance made by melting two or more elements together, at least one of them a metal. An alloy crystallizes upon cooling into a solid solution, mixture, on an intermetallic compound. The components of alloys can not be separated using physical means. An alloy is homogeneous … Read more
Explain the importance of recycling metal? The number of molecules of every element in the world is defined. It is not possible to produce fundamental elements. So every mineral is not infinite, they are finite. The resource of the metal will be finished within 120 – 150 years if we use the metal at the … Read more
What is galvanizing? The method of laying zinc coating on any metal is called galvanizing. It does not require electrolysis. Zinc is coated on anyway on any metal.
Miscible liquids If miscible liquids are to be separated, then this can be done by fractional distillation. The apparatus used for this process is shown in the photo and diagram in Figure and could be used to separate a mixture of ethanol and water. Fractional distillation relies upon the liquids having different boiling points. When … Read more
Immiscible liquids If two liquids are immiscible they can be separated using a separating funnel. The mixture is poured into the funnel and the layers are allowed to separate. The lower layer can then be run off by opening the tap as shown in Figure.
Separating liquid/liquid mixtures In recent years there have been many oil tanker disasters, just like the one shown in Figure. These have resulted in millions of litres of oil being washed into the sea. Oil and water do not mix easily. They are said to be immiscible. When cleaning up disasters of this type, a range of chemicals can … Read more