A change in which one or more new substances are formed is called a chemical change. A chemical change is also called a chemical reaction. example Carbon dioxide (CO2 ) + Lime water [Ca(OH)2 ] → Calcium Carbonate (CaCO3 ) + Water (H2O)When carbon dioxide is passed through lime water, calcium carbonate is formed, which …
one or more new substances are produced in a chemical change. In addition to new products,the following may accompany a chemical change:1 Heat, light or any other radiation (ultraviolet, for example) may be given off or absorbed.2 Sound may be produced.3 A change in smell may take place or4 new smell may be given off.5 …
You must have heard of the ozone layer in our atmosphere. It protects us from the harmful ultraviolet radiation which come from the sun. Ozone absorbs this radiation and breaks down to oxygen. Oxygen is different from ozone. Can we call the breaking down of ozone a chemical change?If ultraviolet radiation were not absorbed by …
This is one change that affects iron articles and slowly destroys them. Since iron is used in making bridges, ships, cars, truck bodies and many other articles, the monetary loss due to rusting is huge.The process of rusting can be represented by the following equation:Iron (Fe) + Oxygen ( O2 , from the air) water …
This process of depositing a layer of zinc on iron is called galvanisation. The iron pipes we use in our homes to carry water are galvanised to prevent rusting.
Stainless steel is made by mixing iron with carbon and metals like chromium, nickel and manganese. It does not rust.
Some substances can be obtained in pure state from their solutions by crystallisation.
Physical changes are changes in the physical properties of substances. No new substances are formed in these changes. These changes may be reversible.
Rusting is the process in which of iron in the presence of moisture and air form a layer of a brownish substance called rust. Both air and moisture are necessary for rusting of iron objects. Due to the presence of the sea, In coastal areas, there is more moisture in the air. But, in the …
Explain why rusting of iron objects is faster in coastal areas than in deserts. Read More »
Take a water-filled beaker and add a few drops of dilute Sulphuric acid into it. Then the water is heated, when it starts boiling slowly add copper sulphate powder during this process stir continuously. Add more copper sulphate till no more powder can be dissolved. The solution is now filtered and allowed to cool down. …
Describe how crystal of copper sulphate are prepared Read More »
