Term
| What is the Maillard reaction and why is it important? |
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Definition
| It is a chemical reaction that occurs between an amino acid and a sugar in the presence of heat. It is responsible for the crust on bread and the browning of meats during cooking. |
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Term
| How many bonds does Boron (B) typically form? |
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Definition
| Three bonds with no lone pairs |
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Term
| How many bonds does lithium (Li) make? |
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Definition
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Term
| Beryllium (Be) forms how many bonds? |
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Definition
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Term
| Elements in ______ do not have to abide by the octet rule. |
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Definition
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Term
| What is an ionic bond? What holds an ionic bond together? |
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Definition
| A bond where one or more electrons from an atom with lower ionization energy are transferred to an atom with greater electron affinity. Typically bonds form between a metal and a nonmetal. The electrostatic force of attraction between opposite charges holds the resulting ions together. |
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Term
| Na+ Cl- is an example of what kind of bond? |
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Definition
| Sodium chloride is an ionic bond. |
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Term
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Definition
| A bond where an electron pair is shared between two atoms with similar electronegativities. Typically the bond is formed between a nonmental and another nonmental. |
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Term
| What determines if a covalent bond is polar? |
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Definition
| The degree to which the pair of electrons is shared equally or unequally between the two atoms. One atom hogging an electron pair will result in a polar molecule. |
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Term
| What is a coordinate covalent bond? |
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Definition
| In a coordinate covalent bond, shared electrons are contributed by only one of the atoms. |
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Term
| Ionic bonds form between atoms with significantly different _____. The atom that loses its electrons becomes a ____. The atom that gains electrons becomes an _____. |
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Definition
| Ionic bonds form between atoms with significantly different electronegativites. The atom that loses its electrons becomes a cation. The atom that gains electrons becomes an anion. |
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Term
| What holds an ionic bond together? |
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Definition
| The electrostatic force of attraction between the opposite charged ions. |
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Term
| True or False: There is sharing of electrons in an ionic bond. |
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Definition
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Term
| Which groups in the periodic table do most ionic bonds form between? |
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Definition
| Between groups IA and IIA and the Halogens. |
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Term
| In an ionic bond, the metal _____ electrons to form a ____. The halogens ___ electrons to form an _____. |
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Definition
| In an ionic bond, the metal loses electrons to form a cation. The halogen gains electrons to form an anion. |
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Term
| What kind of melting and boiling points do ionic compounds have? In what kind of solutions do they dissolve? |
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Definition
| Ionic compounds have very high melting and boiling points. They dissolve in polar solutions such as water. |
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Term
| Ionic compounds are good conductors of electricity in the ____ or ____ states. |
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Definition
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Term
| True or False: Ionic compounds form a crystalline lattice of repeating + and - ions in their solid state. |
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Definition
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Term
| What kind of melting and boiling points do covalent compounds have? Are they good conductors of electricity? Do atoms in covalent compounds share electrons? |
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Definition
| Covalent compounds have weak intermolecular interactions so they have lower melting and boiling points. Covalent compounds are poor conductors. Atoms share electrons in a covalent bond. |
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Term
| Why can't ionic compounds conduct electricity when in a solid state? |
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Definition
| The strong electrostatic forces of attraction in an ionic crystalline lattice prevent movement of the ions and therefore movement of any charges for conduction. |
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Term
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Definition
| The average distance between the two nuclei of the atoms involved in the bond. |
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Term
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Definition
| The number of shared electrons between two atoms. A single bond has a bond order of 1, a double bond has a bond order of 2, and a triple bond has a bond order of 3. |
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Term
| Why are single bonds longer than double bonds and why are triple bonds the shortest bond? |
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Definition
| As the number of shared electrons increases, the two atoms are pulled closer together, leading to a decrease in bond lengths. |
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Term
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Definition
| The energy required to break a bond. |
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Term
| Which type of bond is the hardest to break: single, double, or triple? |
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Definition
| Triple bond. The more shared pairs of electrons between nuclei, the harder the bond will be to break. |
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Term
| How does electronegativity influence polarity? |
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Definition
| The degree of sharing between the nuclei of two atoms in a covalent bond is determined by the relative differences in electronegativity. The more electronegative atom gets the greater share of electrons. |
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Term
| Name the diatomic elements: |
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Definition
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Term
| Polar Covalent bonds occur between atoms of moderately different _____. Between ___ and ____ Pauling Units. |
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Definition
| Polar covalent bonds occur between atoms of moderately different electronegativities. Between 0.4 and 1.7 pauling units. |
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Term
| How do you calculate a dipole moment? |
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Definition
µ = qr
Dipole moment =
charge (coulomb) x distance (meters) |
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Term
| _______ bonds are usually found in Lewis acid-base compounds. |
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Definition
| Coordinate Covalent Bonds |
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Term
| What is a lewis acid and what is a lewis base? |
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Definition
| A lewis acid is any compound that will accept a pair of electrons. A lewis base is any compound that will donate a pair of electrons to form a covalent bond. |
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Term
| Does NH3 usually act as a lewis acid or a lewis base? |
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Definition
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Term
| How do you calculate formal charge? |
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Definition
| Valence electrons in an atom minus dots and sticks. |
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Term
| What is a coordinate covalent bond? Where are they usually found? |
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Definition
| In a coordinate covalent bond, the shared electron pair comes from the lone pair of one of the atoms in the molecule. The other bonded atom contributes nothing. Coordinate covalent bonds are usually found in Lewis acid-base compounds. |
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Term
| You only draw electrons from the ___ and ___ orbitals when drawing lewis structures. |
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Definition
| only the valence electrons from the s and p orbitals. |
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Term
| When drawing lewis structures, extra electrons go on which atom? |
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Definition
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Term
| How can you use formal charge to determine the most stable structure for a compound? |
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Definition
| Add up all the formal charges on each atom for each compound. The structure with the lowest formal charge is most stable/important. |
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Term
| What is a resonance structure? |
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Definition
| Nearly identical lewis structures that differ in electron pair placement but have the same arrangement of atoms. |
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Term
| What is a resonance hybrid? |
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Definition
| The composite of all the possible resonance structures. This is the actual structure of a compound. |
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Term
| What is molecular geometry? |
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Definition
| The spatial arrangement of only the bonding pairs of electrons. However, you also have to take into account how the bonding pairs are moved around by the nonboding pairs. |
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Term
| What is electronic geometry? |
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Definition
| The arrangement of all pairs of electrons around the central atom, including the bonding and lone pairs. |
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Term
| What are the molecular and electronic geometries of NH3? |
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Definition
Molecular is trigonal pyramidal
the electronic geometry is tetrahedral. |
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Term
| Review each of the geometries on the website: http://intro.chem.okstate.edu/1314F00/Lecture/Chapter10/VSEPR.html |
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Definition
| http://intro.chem.okstate.edu/1314F00/Lecture/Chapter10/VSEPR.html |
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