Nine Weeks Chemistry Review

Do molecules generally move faster at 45 C or 106 C?

• 45 C because molecules have more energy than in 106C

• 106 C because molecules have more energy than in 45C

• 106 C because molecules have less energy than in 45C

• 45C because molecules have less energy than in 106 C

When you place the metal in boiling water, heat flows from the _________ to the _______.

• metal to the boiling water

• bottom of the metal to the top half of the metal

• bottom of the water to the top of the water

• boiling water to the metal

DON'T RUSH, YOU HAVE TIME.

Frying an egg on a skillet. Referring to the egg, would the Enthalpy change be positive or negative?

• Skillet is absorbing heat energy from the egg. Absorbing energy is Endothermic. Endothermic has a positive Enthalpy

• Egg absorbing heat energy from the skillet. Absorbing energy is Endothermic. Endothermic has a positive Enthalpy

• Egg absorbing heat energy from the skillet. Releasing energy is Exothermic. Exothermic has a positive Enthalpy

• Egg absorbing heat energy from the skillet. Releasing energy is Exothermic. Exothermic has a negative Enthalpy

Define Exothermic

• Energy is released; ΔH is negative; Going from Gas to Liquid, Liquid to Solid

• Energy is absorbed; ΔH is positive; Going from Gas to Liquid, Liquid to Solid

• Energy is released; ΔH is positive; Going from Solid to Liquid, Liquid to Gas

• Energy is absorbed; ΔH is negative; Going from Gas to Liquid, Liquid to Solid

Define Endothermic

• Energy is absorbed; ΔH is negative; Going from Liquid to Gas, and Gas to Liquid

• Energy is released; ΔH is negative; Going from Solid to Liquid, and Liquid to Gas

• Energy is released; ΔH is positive; Going from Solid to Liquid, and Liquid to Gas

• Energy is absorbed; ΔH is positive; Going from Solid to Liquid, and Liquid to Gas

Is this phase change representing an exothermic or endothermic reaction?

GAS to LIQUID

• Exothermic

• Endothermic

Temperature is a measure of the...

• total energy in a substance
• total kinetic energy in a substance
• average potential energy in a substance
• average kinetic energy of molecules in a substance

It is possible to reach absolute zero

• true
• false

The second  law of thermodynamics states that entropy of a system  tends to ______________. 

• increase
• decrease
• stay constant
• fluctuate wildly

The first law of thermodynamics states that energy is

• created
• destroyed
• conserved
• created and destroyed