Challenging Thermodynamics for NEET

What is the first law of thermodynamics?

• The total energy in a closed system is always increasing.

• Energy conservation principle: ΔU = Q - W.

• Energy can be created or destroyed.

• Work done on a system is equal to the heat lost.

Which law states that energy cannot be created or destroyed?

• Second Law of Thermodynamics

• Law of Conservation of Mass

• First Law of Thermodynamics

• Newton's First Law of Motion

Define enthalpy change in a chemical reaction.

• Enthalpy change is the pressure change during a reaction.

• Enthalpy change is the temperature change at constant volume.

• Enthalpy change is the total energy of a system.

• Enthalpy change is the heat change at constant pressure during a chemical reaction.

What is the standard enthalpy of formation?

• The standard enthalpy of formation is the energy required to break one mole of a substance into its elements.

• The standard enthalpy of formation is the temperature at which a substance changes from solid to liquid.

• The standard enthalpy of formation is the enthalpy change when one mole of a substance is formed from its elements in their standard states.

• The standard enthalpy of formation is the heat released when a substance is burned completely.

How is Gibbs free energy related to spontaneity?

• A process is spontaneous if ΔG > 0.

• A process is spontaneous if ΔG < 0.

• A process is spontaneous if ΔG is positive.

• A process is spontaneous if ΔG = 0.

What is the equation for Gibbs free energy?

• G = H + TS

• G = H / TS

• G = H * TS

• G = H - TS

What does a negative Gibbs free energy indicate?

• A negative Gibbs free energy indicates a spontaneous process.

• A negative Gibbs free energy indicates equilibrium is reached.

• A negative Gibbs free energy indicates an endothermic reaction.

• A negative Gibbs free energy indicates a non-spontaneous process.

Define heat capacity at constant volume.

• Heat capacity at constant volume is the pressure required to change the volume of a system.

• Heat capacity at constant volume is the total energy of a system.

• Heat capacity at constant volume is the amount of heat required to raise the temperature of a system by one degree while keeping the volume constant.

• Heat capacity at constant volume is the amount of work done on a system during expansion.

What is the difference between heat capacity and specific heat?

• Heat capacity is for an entire object; specific heat is per unit mass of a substance.

• Heat capacity measures temperature change; specific heat does not.

• Heat capacity is only applicable to gases; specific heat applies to liquids and solids.

• Specific heat is the total heat of an object; heat capacity is per unit volume.

What is the phase equilibrium condition for a substance?

• The substance cannot change phases under any conditions.

• The temperature is constant regardless of pressure.

• The rates of phase change are equal.

• The substance is in a solid state only.