12th class (Fsc) Chemistry unit 10 MCQs
chapter 10 MCQs 12th Class Chemistry
Alkyl Halides:
1. Which one of the following liquids at room temperature:
a. CH3Br
b. CH3l
c. CH3F
d. C2H5Cl
2. Which one the following is a primary alkyl halide:
a. Tertiary butyl bromide
b. Isopropyl iodide
c. Neo hexyl chloride
d. Secondary butyl iodide
3. Alkyl halides are used for the preparation of:
a. Alkenes
b. Alkanes
c. Alcohols
d. All of these
4. Which one of the following is an explosive:
a. Picric acid
b. Nitro benzene
c. Trinitro benzene
d. Nitro methane
5. The compound which are not found naturally:
a. Carbohydrates
b. Alkanes
c. Alkyl halides
d. Fats
6. Which one of the following nucleophile is good leaving group:
a. OR–
b. OH–
c. Br_
d. NH2–
7. Reduction of aklyl halide in the presence of aqueous acid and Zn forms corresponding:
a. Alkyne
b. Alkane
c. Alkene
d. None of them
8. Reactivity of alkyl halides depends upon.
a. C-X bond energy
b. C-X bond polarity
c. Both of these
d. None of them
9. Decreasing order of reactivity of alkyl halideis:
a. RBr>RCI
b. RI>RCI
c. None of these
d. RI>RBr>RCI
10. Which reagent cannot be used to prepare an alkyl halide from an alcohol:
a. SOCI2
b. NaCI
c. ZnCI2 +HCL
d. PCI5
11. How many structural isomers are possible for C2 H4 Br2 :
a. 3
b. 1
c. 4
d. 2
12. The group which attacks the substrate in S reaction is called:
a. Radical group
b. Electrophile
c. Neutral group
d. Neclophile
13. Nucleophile is usually:
a. Basic and positively charged
b. Basic ain character
c. Basic and negatively charged
d. Acidic in character
14. Poor leaving group is:
a. HSO4–
b. CI
c. NH2–
d. Br
15. Good leaving group is:
a. OH–
b. I
c. OR
d. NH2–
16. The reaction in which halogen is replaced by some other atom or group is called:
a. Oxidation
b. SN reaction
c. Reduction
d. Elimination reaction
17. The alkyklhalide molecule on which a nucleopile attack is called;
a. Electron rich
b. Substrate molecule
c. Alkane molecule
d. Leaving group
18. The method for the preparation of alkyl halides is the reaction of …… with inoganic reagents.
a. Halides
b. Alcohols
c. Organic compounds
d. None of these
19. …… main factor which govern the reactivity of R-X bond:
a. Four
b. Two
c. Three
d. All of these
20. Whenever RMgX reacts with propanone it forms:
a. Sec-alcohol
b. Pri-alcohol
c. Alkane
d. Ter-alcohol
21. OH– ion is a leaving group:
a. Good leaving group
b. Moderate leaving group
c. Both a and b
d. Poor leaving group
22. Alkyls halides are the derivatives of:
a. Benzene
b. Alkane
c. Alkyne
d. None of these
23. The general formula of alkyle halide is:
a. R-CHO
b. R-X
c. R-OH
d. R-NH2
24. R-CH2 -X is an example of:
a. Tertiary alkyl halides
b. Primary alkyl halides
c. Secondary alkyl halides
d. None of these
25. The formula of secondary alkyl halides is:
a. R2 CH-X
b. R-CH2 -X
c. RCH2 OH
d. R3 C-X