Enthalpy definitions crossword (OCR)

1. What is the name of a reaction whereby the enthalpy of the products is smaller than the enthalpy of the reactants ? (this causes heat to be lost to its surroundings). (10)
5. What states that, if a reaction can take place by more than 1 route and the initial and final conditions are the same, the total enthalpy change is the same for each route. (4, 3)
8. What is the enthalpy change that takes place when 1 mol of a substance react completely with oxygen under standard conditions, all reactants and products being in their standard states. (7)
9. What is the enthalpy change that takes place when 1 mol of a compound is formed from its constituent elements in their standard states under standard conditions. (7)

2. what is the physical state of a substance under the standard conditions of 100 kPa (1 atmosphere) and 298 K (25 degrees celsius) (8, 5)
3. What is the enthalpy of formation of an element. (4)
4. An example of an exothermic reaction. (think of animals). (11)
6. What is the enthalpy change that accompanies a reaction in the molar quantities expressed in a chemical equation under standard conditions, all reactants and products being in their standard states. (7)
7. What is a diagram showing alternate routes between reactants and products which allows the indirect determintation of an enthalpy change from other known enthalpy changes using Hess' law. (8, 5)
10. What are: a pressure of 100 kPa, a stated temperature 298 K or (25 degrees celsius) and a concentration of 1.0 mol per dm cubed classed as ? (8, 10)

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