IIT/JEE Chemistry Practice #30: Spontaneity

What is the chemical reaction involved in the conversion of limestone to lime?

• Calcium carbonate to calcium oxide and carbon dioxide

• Calcium oxide to calcium carbonate and oxygen

• Calcium carbonate to calcium hydroxide and water

• Calcium oxide to calcium hydroxide and carbon dioxide

Which condition must be met for a reaction to be spontaneous according to Gibbs Free Energy?

• Delta G must be positive

• Delta G must be greater than zero

• Delta G must be equal to zero

• Delta G must be less than zero

How do you rearrange the inequality to solve for the temperature at which a reaction becomes spontaneous?

• Add T delta S to both sides and divide by delta S

• Multiply delta H by delta S and divide by T

• Subtract T delta S from both sides and divide by delta H

• Add delta H to both sides and divide by delta S

What is the critical temperature above which the conversion of limestone to lime becomes spontaneous?

• 1000 Kelvin

• 500 Kelvin

• 1118 Kelvin

• 298 Kelvin

Why is the conversion of limestone to lime considered entropically favorable?

• It decreases the number of gaseous products

• It releases energy in the form of light

• It absorbs heat from the surroundings

• It produces more substances, including a gas