Chemistry Ch. 16 (Energy and Chemical Change) - Study Guide

Leila is given a sealed flask of sugar water at room temperature. She places it over a Bunsen burner for a few minutes and notes condensation on the sides. Then she places the flask in an ice bath for ten minutes, and notices that ice crystals begin to form. What would Leila know that cannot be true?

• The total energy in the sugar water at the beginning of the experiment is greater than at the end of the experiment

• The total energy in the sugar water remains constant throughout the experiment

• The total energy in the sugar water increases during the experiment

• The total energy in the sugar water decreases during the experiment

For 3.00 g of aluminum foil heated from 20.0°C to 662.0°C, absorbing 1728 J of heat, the specific heat of aluminum is:

• 897 J/(kg·K)

• 935 J/(kg·K)

• 775 J/(kg·K)

• 1002 J/(kg·K)

Spontaneous processes always result in what?

• an increase in entropy

• a decrease in entropy

• no change in entropy

• an increase in free energy

The values resulting in a spontaneous reaction are ΔG < 0.

• ΔG < 0

• ΔG > 0

• ΔG = 0

• ΔG ≠ 0

Reactions with negative Gibbs free energy (negative ΔG) are considered spontaneous at 25°C.

• Exergonic reactions

• Endergonic reactions

• Non-spontaneous reactions

• None of the above

The heat content of a system at constant pressure is called ________.

• Enthalpy

• Internal energy

• Entropy

• Gibbs free energy

For the reaction below, the enthalpy change is +624.7 kJ. How would you classify this reaction? SiO₂(g) + 3C(s) → SiC(s) + 2CO(g)

• Endothermic reaction, heat is gained by the system

• Exothermic reaction, heat is released by the system

A burger contains 220 nutritional Calories. What is the number of joules of this burger?

• 920,000 J

• 880,000 J

• 1,000,000 J

• 840,000 J

Energy that is available to do work is what?

• free energy

• potential energy

• kinetic energy

• total energy

What does the first law of thermodynamics state? ANSWER: energy is neither created nor destroyed in chemical reactions

• energy is neither created nor destroyed in chemical reactions

• energy is always created during chemical reactions

• energy can be created or destroyed under certain conditions

• energy is only conserved in open systems