1 Mark => CHAPTER 13 HYDROCARBONS Questions Answers

ONE MARK QUESTIONS

Q.1. What are hydrocarbons?
Ans. Compounds of hydrogen and carbon.

Q.2.What is the general formula of alkanes?
Ans. C_nH_2n+2

Q.3. Write the general formula of alkenes.
Ans. C_nH_2n

Q.4. What is the general formula of alkynes?
Ans. C_nH_2n-2

Q.5. Give the IUPAC name of lowest molecular weight alkane that contains a
quaternary carbon.
Ans. 2,2dimethylpropane.
Q.6. Arrange the following in the increasing order of C-C bond length- C₂H₆  ,   C₂H₄   ,  C₂H₂
Ans. C₂H₂ < C₂H₄ < C₂H₆

Q.7. Out of ethylene and acetylene which is more acidic and why?
Ans. Acetylene, due to greater electonegativity of the sp hybrid carbon.

Q.8. Name two reagents which can be used to distinguish between ethene and ethyne.
Ans.Tollen‘s reagent and ammonical CuCl solution.

Q.9. Arrange the following in order of decreasing reactivity towards alkanes.
HCl, HBr, HI, HF
Ans.HI> HBr> HCl >HF

Q.10.How will you detect the presence of unsaturation in an organic compound?
Ans. Generally Unsaturated organic compound decolourise Bayer‘s reagent
and Bromine water.

Q.11.What is Grignard reagent?
Ans. Alkyl magnesium halides.