Enthalpy changes

Question 1

The total chemical energy inside a substance is called the

Answer 1

enthalpy (or heat content

Question 2

When chemical reactions take place, changes in chemical energy take place and therefore the enthalpy changes

An enthalpy change is represented by the symbol

Answer 2

ΔH (Δ= change; H = enthalpy)
An enthalpy change can be positive or negative