OBJECTIVE LIFE SCIENCE
BIOCHEMISTRY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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the difference in molecular mass of the two molecules
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covalent bonding
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ionic bonding
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hydrogen bonding
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Detailed explanation-1: -Large amount of energy is required to break these intermolecular hydrogen bonds. Hence, the boiling point of H2O is very high and it is a liquid. Intermolecular hydrogen bonding is not possible in H2S. Hence, its boiling point is lower and is a gas.
Detailed explanation-2: -So, lesser energy is required to overcome the forces of interaction between the hydrogen sulphide molecules than those between water molecules. This energy is available at room temperature and hence, hydrogen sulphide is a gas, while water is still a liquid.
Detailed explanation-3: -The strength of the dipole-dipole forces in liquid H2S is weaker than that of the dipole-dipole forces in liquid H2O. The net dipole moment of the H2S molecule is less than that of the H2O molecule.
Detailed explanation-4: -Therefore, relative molecular mass of hydrogen sulphide ( H 2 S ) = 34 a.m.u.