LABORATORY REVIEW
MOLECULAR BIOLOGY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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Water has a higher boiling point
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Water freezes at a lower temperature
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water has stronger intermolecular forces
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water has a higher heat capacity
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Detailed explanation-1: -Differences between Water and Methane Water is polar and can form intermolecular hydrogen bonds (due to high electronegativity of oxygen atom) Methane is non-polar and can only form weak dispersion forces between its molecules (carbon has a lower electronegativity)
Detailed explanation-2: -(a) Water forms hydrogen bonds and methane only form dispersion forces.
Detailed explanation-3: -Answer and Explanation: The reason water has a significantly much higher boiling point than methane is that water molecules have hydrogen bonds between them. The dipole across the C−H bond is very weak because carbon and hydrogen have very similar values of electronegativity.
Detailed explanation-4: -Water has a DHvap of 40.7 kJ/mol and Methane has a DHvap of 8.2 kJ/mol. Methane is actually a gas at room temperature because of its low heat of vaporization.