Entropy and Enthalpy

If the enthalpy of the products > reactants then this reaction is said to be

• spontaneous

• endothermic

• exothermic

• unlikely

Tags

NGSS.HS-PS1-4

According to Hess' law, if you reverse a reaction

• the sign of delta H must flip

• you do not change the delta H sign

• you must multiply the delta H value by 2

• you must divide the value of delta H by 2

The change of reactants into products will always be spontaneous if the products, compared to the reactants, have

• lower enthalpy and lower entropy

• higher enthalpy and lower entropy

• higher enthalpy and higher entropy

• lower enthalpy and higher entropy

Which of the following two conditions will favor a spontaneous reaction?

• a decrease in entropy and an increase in enthalpy

• a decrease in entropy and a decrease in enthalpy

• an increase in entropy and an increase in enthalpy

• an increase in entropy and a decrease in enthalpy

Tags

NGSS.HS-PS3-4

Given the change of phase: CO₂(g) changes to CO₂(s), the entropy of the system

• remains the same

• You cannot determine the answer with the given information.

• increases

• decreases

The changes in ice to water involve

• and absorption of heat and an increase in entropy

• a release of heat and an increase in entropy

• a release of heat and a decrease in entropy

• an absorption of heat and a decrease in entropy

Tags

NGSS.HS-PS3-4

Based on the equation △G = △H - T△S, a chemical reaction will most likely occur spontaneously if

• △H is + and △S is +

• △H is - and △S is +

• △H is - and △S is -

• △H is + and △S is -

Which of the following processes has a negative △S

• evaporating 1 mol of a liquid

• freezing 1 mol of a liquid

• raising the temperature of 1 L of water from 295 K to 350 K

• None of the other answer are correct.

the total heat content of a system

• enthalpy

• entropy

• temperature

• thermometer

Tags

NGSS.HS-PS3-4

the degree of disorder or randomness in a system

• enthalpy

• entropy

• temperature

• heat