Jeopardy Q $100 Q $100 Q $100 Q $100 Q $100 Q $200 Q $200 Q $200 Ouch! That’s Hot! Counting Those Calories Name that phase change What a gas! NRG definitions Q $100 Q $100 Q $100 Q $100 Q $100 Q $200 Q $200 Q $200 Q $200 Q $200 Q $300 Q $300 Q $300 Q $300 Q $300 Q $400 Q $400 Q $400 Q $400 Q $400 Q $500 Q $500 Q $500 Q $500 Q $500 Final Jeopardy

$100 Question from What a Gas As a beaker of water freezes, is the potential energy of the water increasing, decreasing or remaining constant?

$100 Answer from What a Gas Decreasing

$200 Question from What a Gas If a liquid in a closed container is warmed, its vapor pressure will do this

$200 Answer from What a Gas increase

$300 Question from What a Gas As attractive forces between molecules increase, one would expect the vapor pressure of the substance to do this.

$300 Answer from What a Gas decrease

$400 Question from What a Gas 100 mL of octane was placed on a hot plate and 100 mL of water was placed on a second hot plate at the same temperature Setting. After 30 minutes only 60 mL of octane remained in the beaker whereas 90 mL of water remained. How do you explain this difference in final volumes?

$400 Answer from What a Gas Octane is a nonpolar molecule with weak IMF’s and therefore evaporates more easily.

$500 Question from What a Gas Explain how a pressure cooker works.

$500 Answer from What a Gas Pressure cookers cook food at a higher temperature because the water vapor increases the pressure on the surface of the liquid in the closed system. This makes the boiling point of the water increase and the food cooks faster.

$100 Question from Ouch! That’s Hot! When the rate of evaporation of a liquid equals the rate of condensation in a closed system, the system has reached this condition.

$100 Answer from Ouch! That’s Hot! Dynamic equilibrium

$200 Question from Ouch! That’s Hot! When water vapor condenses in a closed system, one would expect the temperature of the vapor to do this.

$200 Answer from Ouch! That’s Hot! increase

$300 Question from Ouch! That’s Hot! Given the vapor pressure curves above, name the substance with the weakest attractive forces

$300 Answer from Ouch! That’s Hot! pentane

$400 Question from Ouch! That’s Hot! Arrange the boiling point of water at the following locations from highest to lowest: Top of Mount Washington, N.H. Top of Hanover High School Top of Mount Everest

$400 Answer from Ouch! That’s Hot! Top of Hanover High School Top of Mount Washington Top of Mount Everest

$500 Question from Ouch! That’s Hot! Go to the board and sketch a potential energy diagram for a reaction in which the temperature of the surroundings cools. Be sure to label the x and y axes.

$500 Answer from Ouch! That’s Hot!

$100 Question from NRG definitions “The temperature at which the vapor pressure of a liquid is equal to or greater than the external pressure” defines this term.

$100 Answer from NRG definitions Boiling point

$200 Question from NRG definitions “The amount of heat needed to raise the temp of an object 1 degree Celsius” defines this term.

$200 Answer from NRG definitions Heat capacity

$300 Question from NRG definitions A number (including the unit) that represents the amount of heat needed to raise the temperature of 1 gram of water 1 degree celsius.

$300 Answer from NRG definitions 4.18 joules or 1 calorie

$400 Question from NRG definitions “The amount of heat needed to raise the temperature of one gram of a substance by one degree Celsius” is the definition for this term.

$400 Answer from NRG definitions Specific heat capacity

$500 Question from NRG definitions The heat content of a system is the definition for this term.

$500 Answer from NRG definitions Enthalpy

$100 Question from Counting Those Calories The sign for the change in enthalpy in an endothermic reaction

$100 Answer from Counting Those Calories Positive

$200 Question from Counting Those Calories Calculate the enthalpy change in kJ when 45.2 g of steam at 100°C condenses to water at the same temperature Δ H vap for H2O = 40.7 kJ/mol

$200 Answer from Counting Those Calories -102 kJ

$300 Question from Counting Those Calories The amount of heat 32.0 g of water absorbs when it is heated from 25.0°C to 80.0°C (correct sig figs please).

$300 Answer from Counting Those Calories 1,760 calories or 7,360 joules

$400 Question from Counting Those Calories The amount of heat (in kJ) produced when 34.8 g of methane burns ΔH = -890.2 kJ/mol (Report your answer with correct sig Figs!)

$400 Answer from Counting Those Calories -1940 kJ

$500 Question from Counting Those Calories A 30.0 gram sample of a metal is heated From 22.0°C to 59.2°C. During the process, 1.0 kJ of energy is absorbed by the metal. What is the specific heat of the metal? (correct sig figs please).

$500 Answer from Counting Those Calories 0.90 J/g°C

$100 Question from Name That Phase Change The name for the heat released when a substance changes phase from gas to liquid.

$100 Answer from Name That Phase Change Heat of Solidification

$200 Question from Name that Phase Change Water freezing - exothermic or endothermic phase change?

$200 Answer from Name That Phase Change exothermic

$300 Question from Name That Phase Change The opposite of heat of condensation

$300 Answer from Name That Phase Change Heat of vaporization

$500 Question from Name That Phase Change Calculate the heat in kJ associated with a 250.0 gram sample of steam at 100.0°C changing phase to a liquid at 100.0°C. The heat of vaporization of water is 2,260J/g. Be sure your answer shows whether the change is exothermic or endothermic.

$500 Answer from Name That Phase Change -565kJ

$400 Question from Name That Phase Change Watch the demonstration of iodine being heated at the lab bench. What is the name of this phase change?

$400 Answer from Name That Phase Change sublimation

Final Jeopardy Using the standard heat of formation table in your textbook on page 530, and the skeleton equation below, calculate the amount of energy associated with the combustion of 1 mol of hydrogen sulfide. (∆Hfo for H2S = -20.1 kJ/mol) H2S(g) + O2(g) --- H2O(g) + SO2(g)

Final Jeopardy Answer -518 kJ/mol