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 »
Chemical change is the burning of wood and cutting of wood is a physical change. The burning of wood produces ash and smoke that means two new substances are formed. Wood (cellulose ) changes into ash , carbon dioxide and water . Hence the properties of wood are changed. So, it’s a chemical change. When …
When some sour substance or curd ( lactobacillus bacteria ) is added to milk and kept long time, it turns into curd. Once the curd is formed, then there is no way curd can be converted back into milk. Both milk and curd are different and they have different properties So, the formation of curd …
How would you say that setting of curd is chemical change ? Read More »
The wax of the candle melts, then vaporizes and burns. Here Melting of wax is a physical change as no new substance is formed and the melted wax can be converted back to solid wax. When the wax burns, two new substances are formed which are water and carbon dioxide. So, it’s a chemical change. …
Rusting is the process in which iron in the open air acquires a iayer of a brownish substance called rust. For rusting, iron should be in contact with both air and moisture. When an iron gate is painted then the layer of paint cuts off the contact between air, moisture from iron. Thus, it prevents …
Explain how the painting of an iron gate prevents it from rusting. Read More »
