Delta h, or enthalpy change, is a measure of the heat energy released or absorbed during a chemical reaction. It is important in chemistry because it helps us understand the thermodynamics of a reaction and can predict whether a reaction will be exothermic (releases heat) or endothermic (absorbs heat).
To calculate delta h for a chemical equation, you need to know the enthalpy values of the reactants and products. Then, you can use the formula delta h = sum of products - sum of reactants. This will give you the change in enthalpy for the reaction.
Delta h is typically expressed in units of Joules (J) or kilojoules (kJ). However, sometimes it may also be expressed in units of calories (cal) or kilocalories (kcal).
Yes, delta h can be negative. A negative delta h value indicates that the reaction is exothermic, meaning that heat is released during the reaction. This can be seen in reactions such as combustion or neutralization.
Temperature does not directly affect delta h, as it is a measure of the enthalpy change for a specific reaction. However, temperature can indirectly affect delta h by influencing the rate of the reaction, which can impact the overall enthalpy change.