Energetics

Question 1

What is the definition of standard enthalpy of formation?

Answer 1

The standard molar enthalpy of formation is the enthalpy change when one mole of a substance is formed from its constituent elements under standard conditions, all reactants and products being in their standard states.

Question 2

What is the definition of standard enthalpy of combustion?

Answer 2

The standard molar enthalpy of combustion is the enthalpy change when one moles of substance is completely burnt in oxygen under standard conditions , all reactants and products in their standard states.

Question 3

What is specific heat capacity?

Answer 3

The amount of heat energy needed to raise the temperature of 1g of a substance by 1K.

Question 4

What is the formula for enthalpy change?

Answer 4

q = mc delta T

Question 5

What is Hess’s law?

Answer 5

Hess’s law states hat the enthalpy change or a chemical reaction is the same whatever route is taken from reactants to products.

Question 6

What is bond dissociation energy?

Answer 6

The enthalpy change required to break a covalent bond with all species in the gaseous state.