Arrange the following in the decreasing order of their melting points:
I. Heptane      II. Octane
III. Nonane     IV. Decane

• IV > II > III > I

• IV > III > I > II

• I > II > IV > III

• II > III > I > IV

272.

The most reactive hydrocarbon is :

• methane

• ethane

• ethylene

• acetylene

Which of the following is not a cumulated diene?

• Hexa - 2 , 3 - diene

• Penta - 1 , 3 - diene

• Hexa - 1 , 2 - diene

• Penta - 2 , 3 - diene

What is the product P ?

• 

• 

• 

• Both (a) and (b)

In the eclipsed conformation of ethane, the dihedral angle between the hydrogen atoms of adjacent methyl groups is :

• 60°

• 120°

• 0°

• 180°

The major product of the addition of water molecule to propyne in the presence of mercuric sulphate and dilute sulphuric acid is :

• ethanal

• 2-propanol

• propane

• propanone

Which of the following statements is not an essential feature of an optically active molecule ?

• It will rotate the plane of polarised light

• It will have a non-superimposable mirror image

• It will have no element of symmetry

• It will have an asymmetric carbon atom

The reagent which could distinguish between 1-hexyne and 1-hexene is :

• Ag$({\mathrm{NH}}_3{)}_2^{+}$

• KMnO₄

• Br₂ in CCl₄

• H₂SO₄

Choose the correct reagent required to carry out the transformation :

• Zn + conc. HCl

• conc. H₂SO₄

• Li then H₂O

• H₂/Pt

The heat liberated when 1.89 g of benzoic acid is burnt in a bomb calorimeter at 25°C and it increases the temperature of 18.94 kg of water by 0.632°C. If the specific heat of water at 25°C is 0.998 cal/g-deg, the value of the heat of combustion of benzoic acid is

• 881.1 kcal

• 771.2 kcal

• 981.1 kcal

• 871.2 kcal