standard enthalpy changes

Question 1

define standard enthalpy change

Answer 1

when the enthalpy change occurs under standard conditions(298K and 100Pka) and the elements are in their standard states

Question 2

enthalpy changes found in data books are ________ enthalpy changes

Answer 2

standard

Question 3

what is the symbol for standard enthalpy change

Answer 3

ΔH⦵ (the circle is too big i cant make it small)

Question 4

how would this symbol differ if the reaction occurred under 300K and 150kPa

Answer 4

ΔH, no longer standard

Question 5

define standard conditions

Answer 5

When the temperature is 298K, the pressure is 100 kPa and all substances are in their standard states

Question 6

whats the standard state of oxygen

Answer 6

gas

Question 7

list the four types of standard enthalpy change

Answer 7

-standard enthalpy of reaction
-standard enthalpy of formation
-standard enthalpy of combustion
-standard enthalpy of neutralisation

Question 8

what are the units for all standard enthalpies changes

Answer 8

kJ mol⁻¹

Question 9

define standard enthalpy change of reaction

Answer 9

the enthalpy change when a reaction occurs in the molar quantities shown in the chemical equation, under standard conditions

Question 10

what is the symbol for it

Answer 10

ΔH°ᵣ

Question 11

define molar quantities

Answer 11

the amounts of each substance in moles shown in the balanced chemical equation.

Question 12

in standard enthalpy change of reaction, the enthalpy change is defined using _____ _____

Answer 12

molar quantities

Question 13

define standard enthalpy change of formation

Answer 13

the enthalpy change when one mole of a compound is formed from its elements, under standard conditions.

Question 14

what is the symbol for it

Answer 14

ΔH°f

Question 15

define standard enthalpy change of combustion

Answer 15

the enthalpy change when one mole of a substance is completely burned in oxygen, under standard conditions

Question 16

whats the symbol for it

Answer 16

ΔH°c

Question 17

define standard enthalpy change of neutralisation

Answer 17

the enthalpy change when an acid and a base neutralise to form one mole of water, under standard conditions

Question 18

whats the symbol for it

Answer 18

ΔH°neut