enthalpy definitions

Question 1

define enthalpy chnage

Answer 1

the heat enrgy change help under a constant pressure

Question 2

define enthalpy of formation

Answer 2

the enthalpy change when 1 mole of a substance is formed from it elements. aal products and reactants are held in standard conditions

Question 3

define enthalpy of combustion

Answer 3

the enthalpy change when 1 mole of a substance is burned completely in oxygen. products and reactants must be in their standard states

Question 4

is enthalpy of combustion endothermic or exothermic

Answer 4

exothermic

Question 5

is enthalpy of formation endothermic or exothermic

Answer 5

exothermic

Question 6

define enthalpy of neutralisation

Answer 6

enthalpy change when 1 mole of water is formed in a reaction between an acid and an alkali. all products and reactants must be in standard consitions

Question 7

define first ionistation energy

Answer 7

the enthalpy required for 1 mole of electrons to be lost from a gaseous atom to form 1 mole of gaseous 1+ compound

Question 8

define second ionisation enrgy

Answer 8

the enthalpy required to remove 1 mole of electrons from a gaseous 1+ ion to form a gaseous 2+ ion

Question 9

define first electron affinity

Answer 9

enthalpy change when each atom in one mole of a gaseous gains one electron to form 1 mole of gaseous 1- ions

Question 10

define second electron affinity

Answer 10

enthalpy change when each ion in one mole of a gaseous 1- ion gains an electron to form a gaseous 2- ion

Question 11

define enthalpy of atomisation

Answer 11

enthalpy change when one mole of gaseous atoms are produced from an element in its standard state

Question 12

is enthalpy of atomisation endothermic or exothermic

Answer 12

endothermic

Question 13

define hydration enthalpy

Answer 13

enthalpy when 1 mole of gaseous ions ions become hydrated

Question 14

is enthalpy of hydration endothermic or exothermic

Answer 14

exothermic

Question 15

define enthalpy of solution

Answer 15

enthalpy change when 1 mole of ionic solid is completly dissolved to infinite dilution

Question 16

define infinite dilution

Answer 16

that substances have no exertion on other substances. the ions will not interact with each other

Question 17

define bond dissociation energy

Answer 17

enthalpy change required to break 1 mole of bonds in a gaseous substance

Question 18

define lattice enthalpy of formation

Answer 18

enthalpy change when 1 mole of solid ionic compound is formed from its constituent ions in the gas state

exothermic

Question 19

define lattice enthalpy of dissociation

Answer 19

enthalpy change when one mole of a solid ionic compound is broken into its constituent ions in the gas phase

endothermic

Question 20

define enthalpy of vaporisation

Answer 20

enthalpy change when one mole of liquid is turned to gas

exotheric

Question 21

define enthalpy of fusion

Answer 21

enthalpy change when one mole of solid is turned to liquid

endothermic

Question 22

what is the biggest factor affecting enthalpy of atomistaion

Answer 22

CHARGE

BUT shielding is still a factor