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WorksheetsThermo
Total questions: 35
Worksheet time: 1hrs 12mins
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.
Water droplets condensing on the inside of a window on a cold day. Is this process exothermic or endothermic?
Gases condense to form liquids. Gases are moving faster than liquids, the air around the window has a higher temperature/kinetic energy. Releasing energy to get water droplets, which is is Exothermic
Gases condense to form liquids. Gases are moving faster than liquids, the air around the window has a higher temperature/kinetic energy. Releasing energy to get water droplets, which is is Endothermic
Gases condense to form liquids. Gases particles are moving slower than liquids. Releasing energy to get water droplets, which is is Endothermic
Gases condense to form liquids. Gases particles are moving slower than liquids. Releasing energy to get water droplets, which is is Exothermic
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 ΔH
Change in Specific Heat; Heat by one Degree Celsius
Change in Temperature; the energy we calculate; Degree Celsius
Change in Enthalpy; the energy/heat we calculate
Change in Time; time travel
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
Specific Heat is..
the temperature initial minus temperature final
the amount of heat/energy required to raise 1 gram of a substance by 1°C (or K) aka "C"
the temperature final minus temperature initial
the item in a system with given weight in grams
READ CAREFULLY! YOU HAVE TIME!
A substance with a low specific heat requires less energy to heat up and a substance with high specific heat require more energy to heat up and heats up slower
TRUE
FALSE
YOU HAVE TIME!
How much energy is needed to raise the temperature of a 20.0g piece of copper from 15.0 degrees Celsius to 25.0 degrees Celsius? (The specific heat of copper is 0.385 J/g C)
20 X (25-15) =70 J
20 X .385 X (25-15)= 77 J
20 X .385 X (15-25)= 62 J
20 X .385 X (15-0)= 77 J
Is this phase change representing an exothermic or endothermic reaction?
GAS to LIQUID
Exothermic
Endothermic
Is this phase change representing an exothermic or endothermic reaction?
GAS to LIQUID
Exothermic
Endothermic
Is the phase change representing an exothermic or endothermic reaction?
SOLID to LIQUID
Endothermic
Exothermic
Is the reaction exothermic or endothermic?
H2 + S + O2 -> H2SO4 ΔH = -811.13kJ
ΔH is negative so it is exothermic
ΔH is positive so it is exothermic
ΔH is positive so it is endothermic
ΔH is negative so it is endothermic
Is this reaction endothermic or exothermic?
To freeze water …
energy must be added to the water
energy must be removed from the water
An electric stove top works primarily through
thermal conduction
thermal convection
thermal radiation
A reaction has both positive ∆S° and ∆H° values. From this information alone, you can conclude that the reaction
can be spontaneous at any temperature.
cannot be spontaneous at high temperatures.
can be spontaneous only at low temperatures.
can be spontaneous only at high temperatures.
A student volunteers to bring ice tea to a class picnic. She boils water to which she has added tea bags. Time is running short, so she places hot tea into an insulated, steel container, adds some ice cubes then seals the container. Assume that there is no heat exchange with the surroundings. Which of the following would be true?
The total energy and entropy both remain the same.
The total energy decreases while the entropy increases.
The total energy and entropy decreases.
None of the above.
Which of the following is true when ice melts?
∆H<0 ∆S<0
∆H=0 ∆S=0
∆H<0 ∆S>0
∆H>0 ∆S>0
In which of the following four processes is there an increase in entropy?
all of the above
I and II only
I and IV only
III and IV only
At a certain temperature C(s) + O2 (g) ⟶ CO2 (g) has a ∆G of -339.4 kJ. This means that at this temperature
the system is at equilibrium.
gaseous carbon dioxide is unstable.
gaseous carbon dioxide spontaneously forms.
this system has a high reaction rate.
When propane burns in air, heat is released:
C3H8 (g) + 5O2 (g) ⟶ 3CO2 (g) + 4H2O(g)
What are the signs of ∆H, ∆S, and ∆G for this process?
∆H<0 ∆S>0 ∆G>0
∆H<0 ∆S>0 ∆G<0
∆H<0 ∆S<0 ∆G<0
∆H<0 ∆S<0 ∆G>0
