Chem 2023 Spring Semester Review

Breaking bonds ________ energy.

• requires
• releases
• transfers
• destroys

Which of following is NOT true according to the laws of thermodynamics.

• Energy can be transferred from one form to another, but can not be created or destroyed
• The entropy of the universe is always increasing.
• The energy of the universe is always increasing.
• Heat will flow from hot to cold until there thermal equilibrium is reached.

Which of the following is true about the reaction pictured below?

• I and III
• II and IV
• II and III
• I and IV

What is the estimated energy required to break the bonds at the beginning of the reaction pictured?

• 80 kJ
• 160 kJ
• 240 kJ
• 280 kJ

How much heat is released when 125 g of sulfur dioxide are produced according to the following reaction: S + O₂ → SO₂ H = -296 kJ

• -577 kJ

• -296 kJ

• -1156 kJ

• -32 kJ

A 28.4 g sample of metal is heated to 39.4°C, then is placed in a calorimeter containing 50.0 g of water. Temperature of water increases from 21.00°C to 23.00°C. What is the specific heat of the metal? (q=cmΔT, specific heat of water = 4.18 J/g°C)

• 4.18 J/g°C
• 0.897 J/g°C
• 1.345 J/g°C
• 0.374 J/g°C

Liquid water turns to ice. Is this process endothermic or exothermic? Choose the best answer.

• Endothermic. The water absorbed heat and got colder, thereby forming ice.
• Endothermic. Energy in the form of heat was given off by the water, which became colder and formed ice.
• Exothermic. The water released thermal energy, slowing down the water molecules so that solid ice formed.
• Exothermic. Heat was absorbed by the water, moving its molecules faster so that they condensed on an object and formed ice.

Which has the most entropy?

• A
• B
• C
• They all have the same entropy.

Which one of the following processes produces a decrease in the entropy of the system?

• dissolving of solid KCl in water
• mixing of two gases into one container
• freezing water to form ice
• boiling water to form steam

The thermodynamic quantity that expresses the degree of disorder in a system is __________.

• entropy
• internal energy
• heat flow
• enthalpy
• bond energy