Flashcards
hydrogen bonding and structure
Cards in this deck (17)
- 1define hydrogen bodinginteraction between the lone pair of electrons on a nitrogen, oxygen or fluorine atom and a hydrogen atom which is bonded to an N,O or F atom.
- 2describe hydrogen bondsN,O and F are most electronegative atoms . Polar bonds are formed with a hydrogen atom therefore the hydrogen has a strong positive partial change. These are the strongest type of intermolecular forces.
- 3explain the anamolous property of water having higher melting/ boiling point than expectedmany hydrogen bonds between the molecules require more energy to break
- 4explain the anamolous property of ice being less dense than the liquid water.Hydrogen molecules are held apart in open lattice to maximise hydrogen bonding therefore, it lowers the density.
- 5name two types of covalent substances1)simple covalent(simple molecular)
2)Giant covalent (macromolecular) - 6describe simple covalent materials1)atoms bonded by strong covalent bonds
2)molecules held by weak intermolecular forces (3 types)
3)forces relatively low, boiling/ melting point low
4)no mobile charge do not conduct electricity.
5)non polar substances cannot form hydrogen bonds with water. - 7describe structure and properties of diamond1)each atom covalently bonded to 4 other carbon atoms in a tetrahedral arrangement
2)whole crystal has strong covalent bonds therefore,high bp/mp
3)no mobile charge carriers dont conduct electricity
4)giant covalent substances are insoluble in water - 8define ionic bondthe electrostatic attraction between oppositely charged ions
- 9how do ionic bonds occur?atoms become ions by loss or gain of electrons. These electrons are transferred from a metal to non-metal.
- 10what are the properties of giant ionic substances?1)oppositely charged ions occupy a regular lattice with strong ionic bonds high mp.
2)dont conduct electricity as a solid because ions are in fixed lattice but can when molten.
3)soluble in water as they dissociate and charged ions can interact with polar water molecules - 11definition of metallic bondelectrostatic attraction between positively charged metal ions and delocalised electrons
- 12explain structure and properties of metallic bonds1)strong attraction between positive metal ions and delocalised electrons high mp
2) metal ions arranged regurlary in a giant lattice delocalised electrons are free to move through lattice
3)insoluble in water as there are no interactions with molecules - 13properties of gaint ionic compounds1) high mp-fixed arrangement strong attraction alot of energy needed to remove particle from lattice
2)soluble in water and not organic solvents-interaction between polar water mols and charged ions
3)conduct elec when molten not when solid-ions free to move can carry charge - 14properties of simple molecular substances1)low mp-weak9 forces little energy required
2)insouble in water soluble in organic solvents-can interact through weak intermolecular forces such as van der waals not interact with water
3)do not conduct electricity- no charged particles - 15properties of macromolecular substances1)high mp-strong covalent bonds
2)conduct electricity- diamond,silicon dioxide contain no charged particles but Graphite contains free electrons
3)malleable or brittle-diamond,silicon dioxide brittlr breaking bond cracks crystal but graphite is malleable as layers are free to move over each other - 16properties of giant metallic substances1)high mp-strong forces of attraction between positively charged metal ion and delocalised electron
2)conduct electricity-delocalised electrons free to flow
3)malleable and ductile-positive ions can slide past each other whilst retaining strong forces between particled in new arrangement - 17describe gaint covalent materials (example graphite)1)each graphite carbon atom is covalently bonded to 3 other carbon atoms in a hexagonal arrangement in layers.
2)covalent bond require lareg amount of energy to break, high mp/bp
3)carbon atoms have 4 electrons but uses 3 one available, conduct electricity
4)graphite is insoluble in water there are no interactions with water molecules
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- A2 Chemistry Flashcards on hydrogen bonding and structure, created by Bairu .. on 01/08/2018.
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- Bairu ..
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