Term
| What are chemical reactions? |
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Definition
| Making and breaking of chemical bonds |
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Term
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Definition
| Amount of energy required to break a bond. Used only for gaseous species. |
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Term
| What are the three types of intramolecular bonds? |
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Definition
1. Ionic Bonds
2. Covalent Bonds
3. Polar Covalent Bonds |
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Term
| Define ionic bonding. How is the energy of interaction calculated? |
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Definition
| Electrostatic interactions between oppositely charged ions. Typically involves a metal and a nonmetal. Energy of interaction is calculated with Coloumb's law. |
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Term
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Definition
| Change in energy when gaseous ions are combined to form 1 mol of an ionic solid |
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Term
| What is electron affinity? |
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Definition
| A measurement of the change in energy when an electron is added to a neutral gas atom |
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Term
| What is ionization energy? |
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Definition
| A measurement of the amount of energy needed to remove an electron from a neutral gas atom. |
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Term
| What is electron shielding? |
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Definition
| A description of the ability of an atom's inner electrons to shield the positively-charged nucleus from the valence electrons. |
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Term
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Definition
| Process of going from a solid to a gas state. |
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Term
| What does it mean when we say that energy is a "state function?" |
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Definition
| This refers to the fact that the change in energy in a reaction is path independent and that energy is conserved. Energy is a property. |
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Term
| What are four examples of ways in which we study bonds? |
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Definition
1. Physical properties
2. Solubility characteristics
3. Bond energy
4. Spectroscopy |
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Term
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Definition
| Distance between atoms at which the system has minimum energy. |
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Term
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Definition
| When electrons are shared equally between atoms |
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Term
| What are polar covalent bonds? |
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Definition
| When electrons are unequally shared between atoms |
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Term
| What is an essential characteristic of polar covalent bonds? |
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Definition
| The resulting molecule typically has a dipole moment. |
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Term
| How are dipole moments (µ) measured? What happens if µ=0? If µ≄0? |
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Definition
| µ=Q*r, where Q is a charge and r and µ can be measured experimentally. µ is measured in Debye. If µ=0, then the molecule is non-polar, and if µ≄0, then the molecule is polar. |
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Term
| Why don't all molecules with polar bonds have a dipole moment? |
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Definition
| Lone electron pairs and molecular structure affect dipole moment (ie. a linear arrangement cancels the dipole moment). |
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Term
| Ionic character increases as ________ increases. |
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Definition
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Term
| Percent ionic character of a bond |
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Definition
| (Measured dipole moment)/(Calculated dipole moment) x 100 |
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Term
| What is the average energy of a single covalent bond? |
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Definition
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