3.1 Physical Chemistry: .3 Bonding Flashcards Preview

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Flashcards in 3.1 Physical Chemistry: .3 Bonding Deck (68)
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1

what are the ions involved in these compounds;

Hyrdochloric Acid

sulphuric acid

Nitric Acid

Ethanoic Acid

Carbonoic Acid

Phosphoric acid

Sodium Hydroxide

Ammonium

Hydrochloric acid= H+ ... Cl-

sulphuric acid= H+ H+ ... SO42-

Nitric Acid= H+ ... NO3-

Ethanoic Acid= CH3COO- ... H+

Carbonoic Acid= H+ H+ ... CO32-

Phosphoric acid= H+ H+ H+ ... PO43-

Sodium Hydroxide= Na+ ... OH-

Ammonium= NH4+ ... OH-

 

2

work out the formula of the compound when you have these following substances;

-Aluminimum Chloride

-Aluminium Sulphate

-Aluminium Nitrate

-Aluminium carbonate

-Aluminium Phosphate

-Aluminium Hyrdoxide

To work this out, you find out the charge on aluminium when it has become stable and the charge of the acids or hydroxide. The formula will depend on the amount of ions you need to cancel out the opposite charge.

-Aluminimum Chloride= Al3+  Cl( AlCl3 )

-Aluminium Sulphate= Al3+  SO42- ( Al2 (SO4)3 )

-Aluminium Nitrate= Al3+  NO3- ( Al(NO3)3 )

-Aluminium carbonate= Al3+ CO32- ( Al2 (CO3))

-Aluminium Phosphate= Al3+  PO43- ( AlPO4)

-Aluminium Hyrdoxide= Al3+ OH- ( Al (OH)3 )

3

what are the different types of strong chemical bonds?

ionic, covalent and metallic

4

properties of an ionic bond

-ionic bonds occur between metals and non metals

-electrons are transferred from metal atoms to non metal atoms

-positive and negative ions are formed

-and electrostatic attraction holds positive and negative ions together

5

which chemical has a latice of that of a cube shape and explain what a lattice is

sodium chloride

-a lattice is just a general structure

6

what are the properties of ionically bonded compounds?

-always solid at room temp

-ionic compounds can conduct electricity when molten or dissolved not solid because the ions are free to move and they carry a charge, whlist in a solid the ions are in a fixed position by strong ionic bonds

-ionic compounds have high melting points because giant ionic lattices are helf together by strong electrostatic forces and it take high enery to overcome these forces

-Ionic compounds tend to dissolve in water because water molecules are polar. So part of the molecule has a small negative charge and the other a small positive charge. These charged parts pull ions away from the lattice causing it to dissolve,

-ionic compounds are brittle and can shatter easily when given a sharp blow because they form a lattice of alternating positive and negatice ions so a blow may move the ions and produce contact between ions with like charges

7

what  are electrolytes?

electrolytes are ionic salts (e.g Sodium Chloride)

-they conduct electricity as a molten liquid or in solution but not as a solid.

-the ions act as charged carriers

8

what is covalent bond

a shared pair of electrons

9

properties of a covalent bond

-a covalent bond forms between a pair of non-metal atoms

-the atoms share some of their outer electrons so that each atom has a stable noble gas arrangement

-a single covalent bond is shared pair of electrons

10

in a double covalent bond, how many electrons are shared?

4 electrons

11

how does sharing elctrons hold atoms together?

atoms with covalent bonds are held together by the electrostatic attraction between the nuclei and the shared electrons. This takes place within the molecule

12

do covalent bonds break during melting and boiling?

No because during melting and boiling you only overcome  intermolecular forces holding the molecules together in the covalent structures

13

what is coordinate or dative bonding?

where both a pair of electrons comes from one atom

14

show how ammonia NH3 can become NH4+

the nitrogen atom of ammonia uses it lone pair of elctrons to form a coodinate bond with the H+ ions of [an acid maybe].

15

explain the arrangment of cabon atoms in graphite

the carbon atoms are arranged in sheets of flat hexagons covalenty bonded with three bonds each (carbon can make 4 bonds). The fourth outer electron of each carbon is delocalised

-the sheets of hexagns are bonded together by weak van der waals forces

16

what are the properties of graphite?

-the weak bonds between the layers of graphite are easily broken, so the sheets can slide over each other thats why it feels slippery and can be used as dry lubricant

-it is an electrical conductor because the delocalised electron in graphite isnt attached to any particular carbon atom and so is free to move along the sheets carrying a charge

-layers are quite far apart compared to the lenght of the covalent bonds so graphite has a low density and is used to make strong light weight sports equipment

-has a high melting point as energy is needed to overcome the covalent bonds in the hexagonal sheet

-graphite is insoluble in any solvent, the covalent bonds are too strong to break.

17

describe the structure of diamond

diamond is made up of carbon atoms

each carbon is covalently bonded to to four other carbon atoms

the atoms arrange themselves in a tetrahelal shape/

18

what are the properties of diamond?

-diamond has very high melting point because of the strong covalent bonds that require a lot of energy to overcome

-diamond is extremely hard which makes it good for drills and saws

-it is a good thermal conductor because vibrations travel easily through the stiff lattice

- it can not conduct electricity because all outer electrons are used up in bonding

-diamond does not dissolve in any solvent

-you can cut diamond to make gem stones, its structure makes it refract light a lot

19

what is a metallic bond?

metallic bonding involves attraction between delocalised electrons and positive ions arranged in a lattice

20

what would a simple picture of metallic bonding show?

a metal consisting of a lattice of positive ions existing in a sea of out elerctrons which are delocalised.

21

what are the properties of metals?

-metals are good conductors of electricity; the delocalised electrons that carry charge allow electricity to be conducted

-good conductors of heat; they have high thermal conductiviities due to the sea of delocalised electrons which can pass kinectic energy to each other 

-malleable and ductile; malleable (beaten into shape), ductile (pulled into thin wires)

-metals have high metling and boiling points; because they are giant structures. There is a strong attractoin between metal ions and the delocalised sea of electrons which makes the atoms difficult to seperate. The number of delocalised electrons per atom the stronger the bond will be and the higher the melting point e.g Mg2+ has a melting point than Na+

-metals are insoluble because of the strong metallic bonds

22

what does the strenght of a metal depend on?

-the charge of the ion; the greater the charge, the greater the number of delocalised electrons and the stronger the electrostatic force betwee the positiv ions and electrons

-the size of the ions; the smaller the ion, the close the electrons are to the positive nucleus and the stronger the bond.

23

what are the four types of crystal structures?

-ionic

-metallic

-macromolecular

-molecular

24

give an example of a ionic crytal ctructure

and state whether it has a high or low boiling point, what state its in at room temperature, whether it conducts electricity as a solid and a liquid and is soluble in water

sodium chloride (NaCl)

-it has a high melting and boiling point

-it is a solid at room temperature ]

-it does not conduct electricity when solid as there are no freely moving ions but does conduct electricity when liquid as the ions are free to move

-it is soluble in water

 

25

why are ionic crystal structures sobule in water?

-many ionic solids are soluble in water- although not all.

  -It depends on whether there are big enough attractions between the water molecules and the ions to overcome the attractions between the ions themselves.

-Positive ions are attracted to the lone pairs on water molecules and co-ordinate (dative covalent) bonds may form. Water molecules form hydrogen bonds with negative ions.

 

26

give an example of a metallic crystal structure

and state whether it has a high or low boiling point, what state its in at room temperature, whether it conducts electricity as a solid and a liquid and is soluble in water

Magnesium (Mg)

-this crystal structure has a high boiling point

-it is a solid at room temperature

-it does conduct electricity when solid and liquid because of the sea of delocalised electrons

-it is not soluble in water

27

give an example of a macromolecular (giant covalent) crystal structure

and state whether it has a high or low boiling point, what state its in at room temperature, whether it conducts electricity as a solid and a liquid and is soluble in water

-diamiond/ Graphite/ SiO2

-giant covalent crystal structures have high melting and boiling points

-they are solid at room temperatures

-only graphite conducts electrecity because of the lone electron that is able to move along the layer and they can conduct electricity as sublimes rather than liquid

-they are not soluble in water

28

give an example of a molecular (simple covalent)  crystal structure

and state whether it has a high or low boiling point, what state its in at room temperature, whether it conducts electricity as a solid and a liquid and is soluble in water

-Carbon dioxide (CO2)/ Iodine (I2)/ Water (H2O)

-they have a low melting and boiling point because the intermolecular forces dont need a lot of energy but the covalent bonds are still not broken

-Iodine is a solid at room temperature but the other are usually liquid or gas

-they do not conduct electricity when liquid or solid because they have no free electrons as all electrons are used in bonding and they do not have an overall electric charge.

-their solublity depends on how polarised the molecule is

 

29

describe the structure of ice

-each ice molecule forms up to a regular hexagonal lattice out of water molecules which bond to each ther through hydrogen bonding

-the hydrogen bonds form between the lone pair of electrons on the oxygen and the hydrogen atom

30

what are the properties of ice?

-ice has a high melting point compared to other simple molecular structures due to the higher amount of hydrogen bonding

-ice is also less dense than water because when water freezes there is an expansion as the hydrogen bond establishes. Each hydrogen bonds to four others with a tetrahedal arrangement about the oxygen. Hence there is a lot of empty space between molecules of water in ice.