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1) vocab word--the quantity of heat needed to raise the temperature of 1 g of water 1°C2) vocab word--the amount of energy required to raise the temperature of 1 g of a substance 1°C
1) calorie2) specific heat capacity
1) vocab word--the amount of energy required to raise the temperature of 1 mol of a substance 1°C2) vocab word--the study of heat changes that accompany chemical reactions
1) molar heat capacity2) thermochemistry
1) vocab word--a food calorie2) vocab word--the SI unit of heat3) vocab word--chemical reactions that include a heat term
1) Calorie2) Joule
3) thermochemical equation
1) vocab word--a device used to measure the amount of heat absorbed or released during chemical or physical process2) vocab word--the accurate and precise measurement of heat change for chemical and physical processes
1) calorimeter2) calorimetry
1) vocab word--measurement of heat when using constant-pressure calorimetry2) vocab word--form of energy that always flows from a warmer object to a cooler object
1) enthalpy2) heat
1) vocab word—process that absorbs or gains heat from the surroundings2) vocab word—the ability or capacity to do work
1) endothermic2) energy
1) vocab word– the heat change caused by the dissolution of one mole of a substance2) vocab word—the change in enthalpy that accompanies the formation of 1 mole of a compound from its elements
1) Molar heat of solution2) Standard heat of formation
1) vocab word—the heat absorbed by 1 mole of a substance in melting from a solid to a liquid2) vocab word—the amount of heat necessary to vaporize 1 mole of a given liquid
1) Molar heat of fusion2) Molar heat of vaporization
1) vocab word—process that releases or loses heat to the surroundings2) vocab word—states that if you add two or more thermochemical equations to give a final equation, then you can add the heats of reaction to give the final heat of reaction
1) exothermic2) Hess’s Law
Endothermic or Exothermic?
exothermic
Endothermic or Exothermic?
endothermic
Endothermic or Exothermic?
exothermic
Endothermic or Exothermic?
endothermic
Endothermic or Exothermic?
endothermic
Endothermic or Exothermic?
exothermic
Endothermic or Exothermic?
exothermic
Endothermic or Exothermic?
endothermic
Endothermic or Exothermic
endothermic
Endothermic or Exothermic?
exothermic
Endothermic or Exothermic?
4 NO(g) + 6 H2O(l) → 4 NH3(g) + 5 O2(g)
ΔH = +1170 kJ
endothermic
NH3(g) + HCl(g) → NH4Cl(s)
ΔH = −176 kJ
exothermic
Endothermic or Exothermic?
H2(g) + ½ O2(g) → H2O(g) + 286 kJ
exothermic
HgO (s) + 90.7 kJ → Hg (l) + ½ O2 (g)
endothermic
A certain mass of water was heated with 41,840 Joules, raising
its temperature from 22.0 °Cto 28.5 °C. Find the mass of water. The specific heat of water is 4.184
J/(g·C°).
41840 J = m x 6.5C x 4.184 J/g Cm = 1538 g
If it takes 41.72 joules to heat a piece of gold weighing 18.69 g from
10.0 °C to 27.0 °C, what isthe specific heat of the gold?
41.72 J = 18.69 g x 17C x CC = 0.131 J/(g·C°)
Given that the specific heat capacity of gold is 0.131
J/(g·C°), find its molar heat capacity.
.131 𝐽𝑔 ∙℃
×196.97𝑔1𝑚𝑜𝑙
=25.86 𝐽𝑚𝑜𝑙 ∙℃
The temperature of 110 mL of water rises from 25.0°C to 26.2°C when 0.10 mol of H+ is reacted with 0.10 mol of OH-. Calculate the amount of heat released. Assume that the
denisty of the solution is 1.00 g/mL. The specific heat of water
is 4.184 J/(g·C°).
How much heat energy is obtained when 1 kg of ethane gas, C2H6, is burned in oxygen according to the
equation:2C2H6(g) + 7O2(g) → 4CO2(g) +
6H2O(l); ΔH = –3120 kJ
1𝐾𝑔×1000𝑔1𝐾𝑔
×1𝑚𝑜𝑙30.08𝑔
×−3120𝑘𝐽2𝑚𝑜𝑙
=−51,862𝑘𝐽
Determine the energy required to boil 43.89 grams of water at 100.0 °C. The ∆Hvapor of
H2O is 40.67 kJ/mol.
43.89𝑔×1𝑚𝑜𝑙18.02𝑔
×40.67𝑘𝐽1𝑚𝑜𝑙
=99.06𝑘𝐽
What is the value for ΔH for the following reaction?
CS2(l) + 3 O2(g) → CO2(g) + 2 SO2(g)
Given:C(s) + O2(g) → CO2(g); ΔH = -393.5 kJS(s) + O2(g) → SO2(g); ΔH = -296.8 kJC(s) + 2 S(s) → CS2(l); ΔH = 87.9 kJ
Hess’s Law, double 2nd rxn, reverse 3rd rxn
H = -1075 kJ
CH4(g) + 2O2(g) → CO2(g) + 2H2O(l)∆H° = –889.1 kJ
∆Hf° H2O(l) = –285.8 kJ/mol∆Hf° CO2(g) = –393.3 kJ/mol
What is the standard heat of formation of methane, ∆Hf° of CH4(g), as
calculated from the data above?
−889.1 = [−393.3 + 2(−285.8)] −[x + 2(0)] x = ∆Hf° of CH4(g) = −75.8 kJ/mol
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