• icononelinerinfo@gmail.com

Important Chemistry Questions and Answers for Competitive Exams


Important Chemistry Questions and Answers for Competitive Exams

NCERT based chemistry questions and answers which are frequently asked in many competitive exams like JEE Mains, UPSC, SSC, NEET, HSSC, FCI, LDC and TET exams. It includes chemical reactions and equation mcq, chemistry questions on the periodic table etc.


Q 1. How many oxygen atoms are there in one molecule of carbon dioxide ?
Ans. Two
Q 2. This is an enzyme ?
Ans. Trypsin
Q 3. Carbon, diamond, graphite are called as ?
Ans. Allotropes
Q 4. The major ingredient of leather is ?
Ans. Collagen

Q 5. Rayon is chemically ?
Ans. Cellulose
Q 6. Which is commonly called a "poly-amide" ?
Ans. Nylon
Q 7. Nucleus, the genetic material containing rounded body in each cell,was first discovered in 1813 by ?
Ans. Robert Brown
Q 8. Prokaryotic cells lack ?
Ans. Nucleolus, Nuclear membrane, membrane bound by organelles
Q 9. Which is correct sequence in the decreasing order of their densities ?
Ans. Gold> mercury> steel
Q 10. Ordinary table salt is sodium chloride ?
Ans. Sodium bicarbonate
Q 11. The group of metals Fe, Co, Ni may best called as ?
Ans. Transition metals
Q 12. In which activity silicon carbide is used ?
Ans. Cutting very hard substances

Q 13. Which is used as a lubricant ?
Ans. Graphite
Q 14. Tetraethyl lead is used as ?
Ans. Petrol Additive
Q 15. Bromine is a ?
Ans. Red liquid
Q 16. Which metals forms an amalgam with other metals ?
Ans. Mercury
Q 17. Quartz crystals normally used in quartz clocks etc is chemically ?
Ans. Silicon Dioxide
Q 18. Which metals forms an amalgam with other metals ?
Ans. Mercury
Q 19. This element is a metalloid ?
Ans. Silicon
Q 20. The center of an Atom is called ?
Ans. Nucleus
Q 21. This is not a mixture ?
Ans. Mercury.
Q 22. Oxygen and ozone are ?
Ans. Allotropes.

Q 23. Name the most abundant gas in the atmosphere ?
Ans. Nitrogen.
Q 24. Name the gas which is present in electric bulb ?
Ans. Nitrogen.
Q 25. Milk is a ?
Ans. Mixture.
Q 26. _______ is the pure element ?
Ans. Sodium.
Q 27. Air is a ?
Ans. Mixture.
Q 28. Cooking gas is a mixture ?
Ans. Butane and propane.
Q 29. How cooking gas supplied in cylinders by gas agencies is in the form of ?
Ans. Liquid.
Q 30. What is diamond ?
Ans. A pure carbon.