Standard enthalpy change of reaction

Question 1

Standard enthalpy change of reaction meaning

Answer 1

The enthalpy change that takes place for the formation of one mole of gaseous atoms from the element in its standard state under standard conditions.

Question 2

Standard enthalpy change of reaction symbol

Answer 2

ΔHꝊ r

Question 3

Standard enthalpy change of reaction symbol occur in endothermic or exothermic or both

Answer 3

both exothermic and endothermic