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Ch. 2 - Water and Carbon: The Chemical Basis of Life
Freeman - Biological Science 8th Edition
Freeman8th EditionBiological ScienceISBN: 9780138276263Not the one you use?Change textbook
All textbooksFreeman 8th EditionCh. 2 - Water and Carbon: The Chemical Basis of LifeProblem 5
Chapter 2, Problem 5

Which of these molecules would you predict to have the largest number of polar covalent bonds based on their molecular formulas?
a. C2H6O(ethanol)
b. C2H6(ethane)
c. C2H4O2(acetic acid)
d. C3H8O (propanol)

Verified step by step guidance
1
Identify the types of atoms present in each molecule and recall that polar covalent bonds typically form between atoms with different electronegativities, such as between carbon (C) and oxygen (O), or between hydrogen (H) and oxygen (O).
Analyze the molecular formula of each compound: a. C2H6O (ethanol), b. C2H6 (ethane), c. C2H4O2 (acetic acid), d. C3H8O (propanol).
For each molecule, determine the number of oxygen atoms present, as oxygen is more electronegative than carbon and hydrogen, leading to polar covalent bonds.
Count the potential polar covalent bonds in each molecule by considering bonds between carbon and oxygen, and between hydrogen and oxygen.
Compare the number of polar covalent bonds in each molecule to predict which one has the largest number of such bonds.

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Key Concepts

Here are the essential concepts you must grasp in order to answer the question correctly.

Polar Covalent Bonds

Polar covalent bonds occur when atoms with different electronegativities share electrons unequally, resulting in a partial charge distribution. This is common in molecules where atoms like oxygen or nitrogen are bonded to less electronegative atoms such as carbon or hydrogen, creating regions of partial positive and negative charges.
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Electronegativity

Electronegativity is a measure of an atom's ability to attract and hold onto electrons within a chemical bond. Atoms with higher electronegativity, such as oxygen, tend to form polar covalent bonds when paired with atoms of lower electronegativity, like hydrogen or carbon, influencing the molecule's polarity.
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Molecular Structure and Functional Groups

The molecular structure and presence of functional groups, such as hydroxyl (-OH) or carboxyl (-COOH), can indicate the likelihood of polar covalent bonds. These groups contain electronegative atoms that form polar bonds, affecting the molecule's overall polarity and solubility in water.
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Related Practice
Textbook Question

Consider the reaction between carbon dioxide and water to form carbonic acid: CO2(g)+H2O(l)⇌CH2O3(aq) In the ocean, carbonic acid immediately dissociates to form a proton and bicarbonate ion, as follows: CH2O3(aq)+H+(aq)⇌CHO3−(aq) If an underwater volcano bubbled additional CO2 into the ocean, would this sequence of reactions be driven to the left or the right? How would this affect the pH of the ocean?

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Textbook Question

What are the defining characteristics of a condensation reaction?

a. Two monomers are covalently bonded together and a water molecule is produced.

b. Two monomers are covalently bonded together and a water molecule is used up.

c. A polymer is broken down into monomers and a water molecule is produced.

d. A polymer is broken down into monomers and a water molecule is used up.

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Textbook Question

What factors determine whether a chemical reaction is spontaneous or not?

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Textbook Question

Which of these functional groups is known to be used for storing large amounts of chemical energy?

a. Amino group

b. Carbonyl group

c. Phosphate group

d. Sulfhydryl group

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Textbook Question

If you were given a solution that has a pH of 8.5, what would be its concentration of protons? What is the difference in proton concentration between this solution and one that has a pH of 7?

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Textbook Question

Locate fluorine (F) on the partial periodic table provided in Figure 2.2. Predict its relative electronegativity compared to hydrogen, sodium, and oxygen. State the number and type of bond(s) you expect it would form if it reacted with sodium (Na).

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