Chemistry: Thermodynamics!

Enthalpy

100

True or False:

ΔH = H of reactants - H of products

False, it is the other way around.

200

Which is more easily measured?

Change in Enthalpy
Total Enthalpy

Change in Enthalpy

300

Enthalpy is represented by which letter in equations?

H

400

A positive value for ΔH indicates that a reaction is _______.

endothermic

500

H₂O(l) --> H₂O(g)  ΔH = +44.0 kJ/mole

Calculate ΔH for evaporating 45.00g of water

110kJ

Entropy

100

Entropy refers to the amount of _______ in a system.

randomness/chaos/disorder

200

When a system increases in temperature, the entropy ________. (Increases/decreases)

increases

300

True or false: entropy is conserved during a reaction.

False

400

Entropy is represented by which letter in equations?

S

500

H₂O(l) --> H₂O(g)  

ΔS = + or - ?

Positive.

Reactions

100

What is the difference between an exothermic reaction and an endothermic reaction?

Exothermic = net heat transfer system-->surroundings

Endothermic = net heat transfer surroundings-->system

200

True or False: A reaction with a positive ΔG is spontaneous.

False

300

Name two things that are conserved during a reaction.

Mass & Energy

400

complete the equation:

ΔG =

ΔG = ΔH-TΔS

500

True or False: combustion is spontaneous.

True