Podcast
Questions and Answers
The difference in electronegativity values for an ionic bond is usually ______________ than 2.0
The difference in electronegativity values for an ionic bond is usually ______________ than 2.0
greater
London dispersion forces are present in ______________ molecules
London dispersion forces are present in ______________ molecules
nonpolar
Dipole-dipole forces are present only in ______________ molecules
Dipole-dipole forces are present only in ______________ molecules
polar
Hydrogen bonding occurs in molecules with a hydrogen atom bonded to an electronegative atom like fluorine, oxygen, or ______________
Hydrogen bonding occurs in molecules with a hydrogen atom bonded to an electronegative atom like fluorine, oxygen, or ______________
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The force of attraction between molecules is related to their ______________
The force of attraction between molecules is related to their ______________
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Electronegativity difference less than 0.5 results in a ______________ covalent bond
Electronegativity difference less than 0.5 results in a ______________ covalent bond
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Polar molecules have partially positive and negative ends. When two polar molecules are near each other, the ______ end of one molecule is attracted to the ______ end of the other.
Polar molecules have partially positive and negative ends. When two polar molecules are near each other, the ______ end of one molecule is attracted to the ______ end of the other.
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Nonpolar molecules do not have positive or negative ends. Between two neighboring nonpolar molecules, the attraction is very ______.
Nonpolar molecules do not have positive or negative ends. Between two neighboring nonpolar molecules, the attraction is very ______.
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Solubility refers to the ability of a solute to dissolve in a certain amount of ______.
Solubility refers to the ability of a solute to dissolve in a certain amount of ______.
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Rule of thumb 'like dissolves like' is applied to the concept of solubility of ______.
Rule of thumb 'like dissolves like' is applied to the concept of solubility of ______.
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Sucrose is soluble in water because both are ______ molecules.
Sucrose is soluble in water because both are ______ molecules.
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Heat is needed to break the forces of attraction between the ______.
Heat is needed to break the forces of attraction between the ______.
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The ________ element is fluorine.
The ________ element is fluorine.
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The least electronegative or most electropositive element is ________.
The least electronegative or most electropositive element is ________.
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The greater the difference between atom and electronegativity values, the more ________ chemical bonds formed between them.
The greater the difference between atom and electronegativity values, the more ________ chemical bonds formed between them.
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Electronegativity increases from ________ to right and decreases from top to bottom.
Electronegativity increases from ________ to right and decreases from top to bottom.
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Noble gases tend to be an exception to this ________.
Noble gases tend to be an exception to this ________.
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A molecule is polar if electrons are attracted to one end of the molecule more than the other end, resulting in a ________ molecule.
A molecule is polar if electrons are attracted to one end of the molecule more than the other end, resulting in a ________ molecule.
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No center of charge separation means no molecular ______.
No center of charge separation means no molecular ______.
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The water molecule is actually angular, the bond polarities reinforce each other instead of canceling. The positive charge is between the hydrogen atoms, while the negative charge is at the oxygen atom, resulting in polar water ______.
The water molecule is actually angular, the bond polarities reinforce each other instead of canceling. The positive charge is between the hydrogen atoms, while the negative charge is at the oxygen atom, resulting in polar water ______.
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The VSEPR theory states that the shape of many molecules is determined largely by the efforts of the valence shell electrons to stay out of each other’s way to the greatest extent ______.
The VSEPR theory states that the shape of many molecules is determined largely by the efforts of the valence shell electrons to stay out of each other’s way to the greatest extent ______.
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When a hydrogen atom is bonded to Nitrogen, Oxygen, and Fluorine, then it is more likely ______.
When a hydrogen atom is bonded to Nitrogen, Oxygen, and Fluorine, then it is more likely ______.
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Diatomic molecules such as N2, O2, CL2, F2, H2, I2, Br are considered ______.
Diatomic molecules such as N2, O2, CL2, F2, H2, I2, Br are considered ______.
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Noble gases such as Helium, Neon, and Xenon are considered ______.
Noble gases such as Helium, Neon, and Xenon are considered ______.
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HF has higher ______ points than F2.
HF has higher ______ points than F2.
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Methanol (CH3OH) has higher ______ than methane (CH4).
Methanol (CH3OH) has higher ______ than methane (CH4).
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Water is expected to have higher ______ point than carbon dioxide.
Water is expected to have higher ______ point than carbon dioxide.
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Greater amount of heat is needed to break the forces of attraction of ______ molecules compared to non-molecules.
Greater amount of heat is needed to break the forces of attraction of ______ molecules compared to non-molecules.
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Polar molecules have higher ______ points than non-polar molecules.
Polar molecules have higher ______ points than non-polar molecules.
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The boiling point is the temperature at which liquid turns into ______.
The boiling point is the temperature at which liquid turns into ______.
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Study Notes
Ionic and Covalent Bonds
- A difference in electronegativity values of usually more than 2.0 indicates an ionic bond
- Electronegativity difference less than 0.5 results in a non-polar covalent bond
Intermolecular Forces
- London dispersion forces are present in non-polar molecules
- Dipole-dipole forces are present only in polar molecules
- Hydrogen bonding occurs in molecules with a hydrogen atom bonded to an electronegative atom like fluorine, oxygen, or nitrogen
Polarity and Solubility
- Polar molecules have partially positive and negative ends, which attract each other
- Non-polar molecules do not have positive or negative ends, resulting in very weak attraction between them
- Solubility refers to the ability of a solute to dissolve in a certain amount of solvent
- The rule of thumb 'like dissolves like' is applied to the concept of solubility of substances
- Sucrose is soluble in water because both are polar molecules
Electronegativity and Bonding
- The greater the difference between atom electronegativity values, the more polar chemical bonds formed between them
- Electronegativity increases from left to right and decreases from top to bottom in the periodic table
- Noble gases tend to be an exception to this trend
- The least electronegative or most electropositive element is cesium
Molecular Shape and Polarity
- A molecule is polar if electrons are attracted to one end of the molecule more than the other end, resulting in a polar molecule
- No center of charge separation means no molecular polarity
- The VSEPR theory states that the shape of many molecules is determined largely by the efforts of the valence shell electrons to stay out of each other’s way to the greatest extent possible
Hydrogen Bonding
- When a hydrogen atom is bonded to Nitrogen, Oxygen, and Fluorine, then it is more likely to participate in hydrogen bonding
Physical Properties
- Diatomic molecules such as N2, O2, CL2, F2, H2, I2, Br are considered non-polar
- Noble gases such as Helium, Neon, and Xenon are considered non-polar
- HF has higher boiling points than F2
- Methanol (CH3OH) has higher boiling points than methane (CH4)
- Water is expected to have higher boiling point than carbon dioxide
- Greater amount of heat is needed to break the forces of attraction of polar molecules compared to non-polar molecules
- Polar molecules have higher boiling points than non-polar molecules
- The boiling point is the temperature at which liquid turns into gas
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Description
Learn about how the forces of attraction in polar and nonpolar molecules affect their melting and boiling points. Understand why polar molecules generally have higher melting points compared to nonpolar molecules through examples like hydrogen fluoride (HF) and fluorine (F2). Explore the concept of boiling point and how it relates to the temperature at which a liquid turns into gas.