Lec 27 Thermochemical equations

Question 1

What happens to Enthalpy if thermo chemical equation is multiplied by any factor

Answer 1

The delta H is also multiplied by that

Question 2

What happens to Enthalpy if thermo chemical equation is reversed

Answer 2

Sign of delta h is reversed

Question 3

What are units of Enthalpy

Answer 3

kJ/mol-rxn or kJ/mol

Question 4

If Enthalpy postive

Answer 4

Endothermic

Question 5

If Enthalpy negative

Answer 5

Rxn is exothermic

Question 6

Energy lvl diagram look at

Answer 6

Slide 6

Question 7

What is Hess law

Answer 7

Since Enthalpy is a state function, it’s value is the same whether the reaction occurs in one or many steps.

DELTA H is equal to sum of all delta H

Question 8

What are the standard state conditions

Answer 8

1 bar of pressure at 25 degrees or 298K

Question 9

What is the standard state Enthalpy of formation

Answer 9

The Enthalpy of rxn for formation of a substance from its most stable form of elements

Question 10

What is the Enthalpy of standard state elements

Answer 10

0