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Total Time: 35 min
CHAPTER WISE CLASS TEST
(Test # 2)
NOTE: Four possible answers A, B, C and D to each question are given. The choice which you think is correct, fill that circle in front of that question with Marker or Pen ink. Cutting or filling two or more circles will result in zero mark in that question.
TIME: 10 MinOBJECTIVEMARKS: 8
Q.1:(08)
1.The product which will be formed when propene reacts with bromine molecule.
(A) 1,2–Dibromopropane✔(B) 1,1–Dibromopropane(C) 2,3–Dibromopropane(D) 1,3–Dibromopropane
2.The formula of propyne is:
(A) CH2=CH-CH3(B) CH3–C ≡ CH✔(C) CH3-CH = CH2(D) CH3-CH2-CH3
3.Select the name of the petroleum fraction which generates electricity in power plants.
(A) Bitumen(B) Lubricating oil(C) Kerosene oil(D) Fuel oil✔
4.Which of the following is an alkyne?
(A) C2H3(B) C2H6(C) C2H2✔(D) C2H5 OH
5.The molecule eliminated in the following reaction is:
CH3 – CH2 – Br + KOHEthanolCH2 = CH2 + KBr + H2O
(A) Br2(B) H2(C) HBr✔(D) H2O
6.The fractionating column has compartments divided into shelves covered with:
(A) Sand filters(B) Gravel(C) Bubble caps✔(D) Activated carbon
7.Fractional distillation of petroleum is based on:
(A) Viscosity(B) Boiling point range✔(C) Flammability(D) Melting point range
8.Lubricating oil fraction is used for:
(A) Fuel in cars(B) Jet fuel(C) Lubricants, waxes and polishes✔(D) Making roads
TIME: 25 MinSUBJECTIVEMARKS: 17
(PART – I)
Q.2 Write short answers to following questions.(6×2=12)
i.Differentiate between elimination and addition reactions.
Ans: Elimination: a small molecule (such as H2O or HBr) is removed from a saturated compound, forming an unsaturated compound with a double bond. e.g. CH3CH2OH → CH2=CH2 + H2OAddition: atoms or groups add to the double or triple bond of an unsaturated compound, forming a saturated compound. e.g. CH2=CH2 + H2 → CH3–CH3
ii.Write the formula of ethyne and state its IUPAC name.
Ans: Formula: C2H2 (structural formula HC ≡ CH). IUPAC name: ethyne (commonly called acetylene).
iii.How can an alkene be identified?
Ans: By the bromine water test: an alkene decolourises reddish-brown bromine water. It also decolourises pink (purple) KMnO4 solution, whereas an alkane does not.
iv.What is fractional distillation of petroleum.
Ans: The process of separating crude petroleum into its useful fractions on the basis of their different boiling point ranges, carried out in a fractionating column, is called fractional distillation of petroleum.
v.Why is oxyacetylene flame so hot?
Ans: Acetylene burns completely in pure oxygen and releases a large amount of heat: 2C2H2 + 5O2 → 4CO2 + 2H2O + heatThe flame reaches a temperature of about 3000°C, so it is used for welding and cutting metals.
vi.What is the boiling range and use of kerosene oil?
Ans: Boiling range: about 170–250°C. Use: as a fuel for stoves, lamps and heaters, and as jet-engine (aviation) fuel.
(PART – II)
Note: Attempt the following question.
Q.3: Give uses of acetylene.(5)
Ans: (1) Oxyacetylene flame is used for welding and cutting metals. (2) Used for artificial ripening of fruits (from calcium carbide). (3) Used to make plastics such as PVC and synthetic rubber. (4) Used to prepare organic chemicals such as acetic acid and ethanal (acetaldehyde). (5) Used as a source of light in carbide lamps.
