ATOMIC BONDS

Question 1

chemical bond

Answer 1

a mutual attraction between two atoms resulting from the simultaneous attraction between their nuclei and out electrons

Question 2

bonded pair

Answer 2

a pair of electrons that is shared between two atoms in a covalent bond

Question 3

orbital

Answer 3

a region in space around the nucleus where the electrons are most likely to be found

Question 4

non-polar bond

Answer 4

a covalent bond in which both atoms attract the bonding electrons equally

Question 5

polar bond

Answer 5

a covalent bond in which electrons are pulled closer to the atom with higher electronegativity

Question 6

molecule

Answer 6

a group of two or more atoms covalently bonded and that function as a unit

Question 7

lone pair

Answer 7

a pair of electrons in the valence shell of an atom that is not shared with another atom

Question 8

covalent bond

Answer 8

the sharing of electrons between two atoms to form a molecule

Question 9

electronegativity

Answer 9

a measure of the tendancy of an atom in a molecule to attract bonding electrons

Question 10

non-polar molecule

Answer 10

the charge is evenly spread across the molecule

Question 11

valence electrons

Answer 11

electrons in the outermost energy level of an atom

Question 12

polar molecule(dipole)

Answer 12

the charge distribution is uneven across the molecule

Question 13

bond energy of a compound

Answer 13

the energy needed to break one mole of its molecules into separate atoms

Question 14

bond length

Answer 14

the average distance between the nuclei of two bonded atoms

Question 15

interatomic force

Answer 15

an electrostatic force if attraction between atoms due to the sharing or transfer of electrons

Question 16

intermolecular force

Answer 16

an attraction between molecules

Question 17

induced dipole forces

Answer 17

an attraction between atoms or non-polar molecules. (also called London or van der Waals dispersion forces)

Question 18

ion-dipole force

Answer 18

the attraction of an ion with a positive or negative charge and the oppositely charged end of a polar molecule

Question 19

ion-induced dipole force

Answer 19

an attraction between an ion and a non-polar particle

Question 20

dipole-dipole forces

Answer 20

an attraction between polar molecules

Question 21

hydrogen bond

Answer 21

an attraction between molecules that contain bonds between nitrogen, oxygen or fluorine atoms and hydrogen

Question 22

dipole-induced dipole forces

Answer 22

an attraction between a polar molecule and a non-polar particle

Question 23

melting point

Answer 23

the temperature at which the solid and liquid phases of a substance are at equilibrium

Question 24

boiling point

Answer 24

the temperature at which the vapour pressure of a substance equals atmospheric pressure

Question 25

density

Answer 25

mass per unit volume

Question 26

thermal expansion

Answer 26

the increase in volume of a material as its temperature increases

Question 27

thermal conductivity

Answer 27

the ability of a substance to conduct heat

Question 28

ideal gas

Answer 28

a theoretical gas which obeys the gas laws under all conditions of temperature and pressure

Question 29

Boyles law

Answer 29

the pressure of an enclosed gas is inversely proportional to the volume it occupies at constant temperature

Question 30

avogadro's law

Answer 30

one mole of any gas occupied the same volume at the same temperature and pressure

Question 31

one mole

Answer 31

the amount if substance having the same number of particles as there are atoms in 12g carbon-12

Question 32

molar mass

Answer 32

the mass of one mole of a substance measured in g.mol-¹

Question 33

concentration

Answer 33

the amount of solute owr liter of solution

Question 34

molar volume of gas

Answer 34

volume occupied by 1 mole of gas[22.4 dm³ at 0°(273k)] and 1 atmosphere(101.3kpa)

Question 35

standard solution

Answer 35

ant solution that has a precise, known concentration

Question 36

limiting reagent

Answer 36

the reactant that is consumed completely in a reaction. It determines the maximum amount of product that is formed

Question 37

enthalpy

Answer 37

the heat content of a system

Question 38

heat of reaction

Answer 38

the energy absorbed it released per mole in a chemical reaction

Question 39

exothermic reactions

Answer 39

a chemical reaction during which heat energy is released to the surrounding is less than 0(negative)

Question 40

endothermic reaction

Answer 40

a chemical reaction during which heat energy is absorbed from the surroundings. is greater than 0(positive

Question 41

activation energy

Answer 41

the minimum energy required to start a chemical reaction(through initial bond breaking)

Question 42

activated complex

Answer 42

the unstavoe transition state from reactants to products

Question 43

arrhenius theory for an acid

Answer 43

a substance produces hydrogen ions H+/hydronium ions(H3O+) when it dissolves in water

Question 44

arrhenius theory for a base

Answer 44

a substance that produces hydroxide ions(OH-) when it dissolves in water

Question 45

Lowry-brønstead theory for an acid

Answer 45

an acid is a proton(H+ ion) donor

Question 46

Lowry-brønstead theory for a base

Answer 46

a base is a proton(H+ ion) acceptor

Question 47

conjugate acid-base pair

Answer 47

when the acid, HA, loses a proton, its conjugate base, A-, is formed. when the base, A- accepts a proton, its conjugate acid, HA, is formed. these two conjugate an acid-base pair

Question 48

ampholyte

Answer 48

a substance that can act as either acid or base

Question 49

redox reaction

Answer 49

a reaction during which electrons are transferred/oxidation numbers change

Question 50

oxidation

Answer 50

a loss of electrons. An increase in oxidation numbers

Question 51

reduction

Answer 51

a gain of electrons, a decrease in oxidation number

Question 52

oxidising agent

Answer 52

a substance that is reduced/that gains electrons/whose oxidation numbers decreases

Question 53

reducing agent

Answer 53

a substance that is oxidised/that loses electrons/whose oxidation number increases

Question 54

oxidationg number

Answer 54

a number assigned to each element in a compound in order to keep track of the movement of electrons during a reaction