U2-2-1 - Enthalpy of Formation Flashcards
1
Q
Standard values (states, enthalpy, etc) are taken at a temperature of …
A
298 K (25 °C)
2
Q
Standard state
A
The most stable state at a pressure of 1 atm at 298 K.
3
Q
The enthalpy change when 1 mol of a substance is formed from its elements in their standard states.
A
Standard enthalpy of formation
4
Q
For pure elements in their standard states, ∆H°f = …
A
0
5
Q
Why does this equation not represent an enthalpy of formation?
A
2 mol of product (must be 1 mol)
6
Q
Why does this equation not represent an enthalpy of formation?
A
Br is not in its standard (liquid) state
7
Q
Standard enthalpy of formation
A
The enthalpy change when 1 mol of a substance is formed from its elements in their standard states.
