chemistry-important questions and theirs answers

1. Which antiseptic compound is present in Dettol? – Chloroxylenol
2. What is a compound that is a white solid which absorbs water vapour from the air? – Calcium chloride
3. To which product of equivalent weight and valency of an element is equal? – Atomic weight
4. Which element forms the highest number of compounds in the periodic table? – Silicon
5. How does addition of ethylene dibromide help to petrol? – Elimination of lead oxide

6. What do we call the process of separation of pure water from impurities? – Distillation
7. What is the name of gas which is present in both the natural gas and the biogas? – Methane
8. How many elements are in the second period of the periodic table? – Eight
9. Of which alloy the commonly used safety fuse-wire is made? – Alloy of Tin and Lead
10. What is alcohol obtairied in the saponification process? – Glycerol
11. Which is used to dilute oxygen in the gas cylinders used by divers? – Helium
12. What do cathode rays caise when obstructed by metal? –emission of X-rays
13. With which liqued is anomalous expansion associated? – Water
14. What is a tick paste of cement, sand and water called? – Mortar
15. Ethanol containing 5% water By which name is it known? – Rectified spirit
16. Of which Container radioactive materials should be kept? – Pb
17. Which is not an anaesthetic agent in surgical operations? – Acetone
18. What is the percentage of Nitrogen, present in ammonium sulphate? – 21%
19. Which is the nuclear particle having no mass and no charge, but only spin? – Neutrino
20. The pH of fresh milk is 6. When it turns sour, what will be the pH? – Less than 6
21. How must have metals used to make wires for safety fuses? – Low resistivity and low melting point
22. Sodium stearate is a salt and how is it used? – To make soap
23. Which are the two main constituents of granite? – Iron and silica
24. Which method of water purification does not kill microorganism? – Filtration
25. Which gase is supporter of combustion? – Oxygen
26. By which was the presence of Cobalt. in Vitamin B-12 established for the first time? – Borax-Bead test
27. Which metal can deposit copper from copper sulphate solution? – Iron
28. Which group of gases contribute to the “Green House effect”? – Carbon dioxide and Methane
29. On heating, Gypsum loses certain percentage of its water content and what does it become? – Plaster of Paris
30. A liquid initially contracts when cooled down to 4 degree Celsius
but on further cooling down to zero degree Celsius, it expands. What is
the name of liquid? – Water

physics-important questions and theirs answers

Leave a Reply