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The standard enthalpy of formation of an element in its standard state is:

• 1 Negative
• 2 Always 100 kJ/mol
• 3 Positive
• 4 Zero

For an endothermic reaction, the sign of delta H is:

• 1 Positive
• 2 It cannot be known
• 3 Negative
• 4 Zero

Which change leads to an increase in entropy?

• 1 A gas dissolving in water
• 2 Water freezing
• 3 Ice melting
• 4 Steam condensing

A reaction is spontaneous at constant temperature and pressure when:

• 1 Delta G is negative
• 2 Delta G is positive
• 3 Delta S is zero
• 4 Delta H is positive

The heat released by a reaction, 5000 J, is all absorbed by 100 g of water. What is the rise in temperature? (Specific heat of water 4.18 J/g per degree C)

• 1 12 degrees C
• 2 50 degrees C
• 3 5 degrees C
• 4 1.2 degrees C

For a reaction, delta H = +40 kJ and T x delta S = 50 kJ. What is delta G?

• 1 +10 kJ
• 2 +90 kJ
• 3 -10 kJ
• 4 -90 kJ

The heat change of a reaction measured at constant pressure is called the change in:

• 1 Free energy
• 2 Entropy
• 3 Enthalpy
• 4 Internal energy only