# Chapter 16: Thermochemistry Review ```Name: ___________________________________________ Date: ________________ Mods:__________
Chapter 16: Thermochemistry Review
Part 1: Cooling Curve of an Unknown Substance
B
C
D
E
Temperature
F
G
H
Time
Directions: Indicate the letter that best answers the questions:
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1. Where vaporization occurs
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2. Liquid is being heated
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3. Particles have the least molecular movement
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4. Where gas is being heated
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5. Melting occurs here
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6. Where particles exhibit the greatest amount of kinetic energy
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7. Freezing occurs here
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8. Where condensation occurs
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9. Solid is being heated
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10. Particles have a definite shape and volume
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11. Where kinetic energy is the highest
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12. Where kinetic energy is the lowest
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13. Particles have the most molecular movement
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14. Particles have no definite shape or volume
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15. Particles have a definite volume but no definite shape
Part 2: Calculating Specific Heat Worksheet
q = mCp∆T, where q = heat energy, m = mass, and ∆T = change in temp.
Remember, ∆T = (Tfinal – Tinitial). Show all work and proper units.
1. A 15.75-g piece of iron absorbs 1086.75 joules of heat energy, and its temperature changes from 25&deg;C
to 175&deg;C. Calculate the specific heat capacity of iron.
2. How many joules of heat are needed to raise the temperature of 10.0 g of aluminum from 22.8&deg;C to
53.9&deg;C, if the specific heat of aluminum is 0.90 J/g&deg;C?
3. What mass of water will change its temperature by 3.5&deg;C when 525 J of heat is added to it? The
specific heat of water is 4.18 J/g 0C
4. A 0.3 g piece of copper is heated and fashioned into a bracelet. The amount of energy transferred by
heat to the copper is 66,300 J. If the specific heat of copper is 390 J/g 0C, what is the change of the
copper's temperature?
5. Calculate the specific heat capacity of a piece of wood if 1500.0 g of the wood absorbs 67,500 joules of
heat, and its temperature changes from 32&deg;C to 57&deg;C.
Part 3: Thermochemical Equations &amp; Enthalpy Diagrams
1. Determine if the following reactions are endothermic or exothermic:
a) CaO (s) + H2O (l)  Ca(OH)2 (s)

∆H = - 65.2 kJ
Circle One: Do the reactants or products have a HIGHER enthalpy?
b) 2 NaHCO3 (s) + 129 kJ  Na2CO3 (s) + H2O (l) + CO2 (g)

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Circle One: Do the reactants or products have a HIGHER enthalpy?
c) NaOH (s) + H2O (l)  Na+ (aq) + OH-- (aq) + 445.1 kJ

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Circle One: Do the reactants or products have a HIGHER enthalpy?
d) PbCl2 (s) + Cl2 (g)  PbCl4 (l)
∆H = 30.1 kJ
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
Circle One: Do the reactants or products have a HIGHER enthalpy?

Draw and label an Enthalpy Diagram for this reaction below:
e) RbOH (aq) + HBr (aq)  RbBr (aq) + H2O + 55.9 kJ
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
Circle One: Do the reactants or products have a HIGHER enthalpy?

Draw and label an Enthalpy Diagram for this reaction below:
Part 4: Calorimetry
q(gained) = - q(lost)
mCp∆T(gained) = - mCp∆T(lost)
1. A room temperature (27&deg;C) glass statue with a mass of 11.4 g is heated to dropped into 175 g of hot
water at 100.0&deg;C. The final temperature of the water is 97.6&deg;C. What is the specific heat capacity of the
glass statue? (Cp of water is 4.184 J/g&deg;C).
a) Which substance – glass or water- is losing heat (aka: getting cooler)? _________________
Calculate the quantity of heat lost by this substance:
b) Which substance - glass or water- is gaining heat (aka: getting warmer)? __________________
Determine the quantity of heat gained by this substance:
c) Determine the specific heat of the glass statue:
2. A 500.0 g piece of iron is heated in a flame and dropped into 400.0 g of water at 10.0&deg;C. The
temperature of the water rises to 90.0&deg;C. What temperature was the iron initially when it was first
removed from the flame? (Cp of iron is 0.473 J/g&deg;C; Cp of water is 4.184 J/g&deg;C).
a) Which substance - iron or water- is gaining heat (aka: getting warmer)? __________________
Calculate the quantity of heat absorbed by this substance:
b) Which substance - iron or water- is losing heat (aka: getting cooler)? __________________
Determine the quantity of heat lost by this substance:
c) Determine the initial temperature of the iron when it was first removed from the flame:
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