Term
| which type of solid materials are typically hard, have high melting points, and poor electrical conductivities (2) |
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Definition
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Term
| what is a correct description of metallic bonding? (ions to electrons) |
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Definition
| positively charged metal ions are attracted to delocalized electrons |
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Term
| Explain which has a bigger boiling point: CH3COOH or C2H5OH? (4) |
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Definition
CH3COOH has the biggest boiling point because, although they both have hydrogen bonds, CH3COOH has a bigger mass, so its bonds are harder to break;
more electrons, stronger van der Walls;
boiling point is based on intermolecular forces; |
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Term
| Describe the metallic bonding present in aluminum and explain why aluminum has a higher melting point than sodium. (3) |
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Definition
| Metallic bonding in aluminum is between delocalized electrons and positive nucleus. Its melting point is higher than Na because it has a higher mass; more electrons; stronger van der Waals; bonds harder to break. |
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Term
Predict and explain which of the following compounds consist of molecules:
NaCl, BF3, CaCl2, N2O, P4O6, FeS, CBr4(2) |
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Definition
NaCl and CaCl2 are the only compounds that are not compounds;
they have high differences in electronegativity, >1.8 |
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Term
| State the structures of and the bonding in diamond and graphite. (2) |
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Definition
Diamond has carbon bonds that are tetrahedrally arranged , with a 109.5 bond angle.
Graphite has carbon bonds that are held by van der Waals in parallel layers of trigonal bonding. |
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Term
| Compare and explain the hardness and electrical conductivity of diamond and graphite. (4) |
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Definition
Diamond is a poor conductor, because it has no delocalized electrons;
It is extremely hard because it has a rigid structure;
Graphite is a good conductor because it has delocalized electrons;
It is soft because it has layers that can slide. |
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Term
| Predict and explain how the hardness and electrical conductivity of C60 fullerene would compare with that of diamond and graphite. (4) |
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Definition
Fullerene is softer than diamond, but harder than graphite because the molecules can move over each other;
It conducts better than diamond, but worse than graphite;
C60 has less delocalized electrons than graphite; |
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Term
| outline the principles of the valence shell electron pair repulsion (VSEPR) theory. (3) |
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Definition
electron pairs in the outer shell of an atom repel each other and position themselves as far away as possible;
negative charge centers thus determine shape of molecule (double, triple, single bonds all count as one center);
lone pairs of electrons repel the most and cause the most distortion of shape; |
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Term
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Definition
| Electrostatic attraction between oppositely charged ions |
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Term
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Definition
| electrostatic attraction between a pair of electrons and positively charged nuclei |
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Term
| As bond length increases, bond strength... |
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Definition
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Term
| Put the three intermolecular forces in order of strength |
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Definition
| van der Waals, dipole-dipole, hydrogen bond |
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Term
| Describe the metallic bond. |
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Definition
| electrostatic attraction between a lattice of positive ions and delocalized electrons. |
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Term
| Name two physical properties associated with metals. |
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Definition
| malleability, and ductility |
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Term
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Definition
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Term
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Definition
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Term
| bond angle of tetrahedral |
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Definition
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Term
| bond angle of "bent" (only one lone pair) |
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Definition
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Term
| bond angle of "bent" (two lone pairs) |
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Definition
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Term
| Explain the expression "like dissolves like." |
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Definition
Ionic compounds are soluble in polar solvents
covalent compounds are soluble in non-polar solvents |
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Term
| Ionic compounds have ______ structures. |
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Definition
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Term
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Definition
| a bond where one atom shares both electrons |
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