Multiple Choice
Given that the equilibrium constant k for the reaction a(g) ⇌ b(g) is 3.2 × 10^{-3} at 0°C and 8.1 × 10^{-3} at 50°C, what is the enthalpy of vaporization (ΔH_vap) for the process? (Assume R = 8.314 J·mol^{-1}·K^{-1})
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8. Thermochemistry
Thermochemical Equations
Back8. Thermochemistry
Thermochemical Equations
- Multiple ChoiceGiven the following vapor pressure data for a liquid metal at different temperatures, which method would you use to determine the enthalpy of vaporization (ΔH_vap)?Temperature (K): 400, 420, 440, 460Vapor Pressure (atm): 0.12, 0.22, 0.38, 0.65Choose the most appropriate approach:26views
- Multiple ChoiceWhat is the standard enthalpy change (ΔH°) for the reaction: 2 NO(g) + O2(g) → 2 NO2(g)?10views
- Multiple ChoiceGiven the thermochemical equation: 2H2(g) + O2(g) → 2H2O(l)ΔH = -571.6 kJ, what is the heat of reaction (ΔH) for the formation of 1 mole of H2O(l)?43views
- Multiple ChoiceGiven the reaction: N_2O(g) + NO_2(g) → 3 NO(g), what is the standard enthalpy change (ΔH°) for this reaction? (Standard enthalpies of formation: ΔH_f°[N_2O(g)] = 82 kJ/mol, ΔH_f°[NO_2(g)] = 34 kJ/mol, ΔH_f°[NO(g)] = 90 kJ/mol)22views
- Multiple ChoiceWhich of the following phase changes are associated with q > 0 (heat absorbed by the system)?36views
- Multiple ChoiceWhat is the standard enthalpy of formation (ΔH_f^ext{°}) value for CO_2(g) in kJ/mol?31views
- Multiple ChoiceMothballs are composed primarily of the hydrocarbon naphthalene (C10H8). When 0.820 g of naphthalene burns in a bomb calorimeter, the temperature rises from 25.10 °C to 31.56 °C. If the heat capacity of the calorimeter is 5.11 kJ/°C, what is the change in internal energy (ΔErxn) for the combustion of naphthalene?225views
- Multiple ChoiceUsing the given reactions, what is the enthalpy change (ΔH°) for the reaction: 2 CO(g) + 2 H2(g) → CO2(g) + H2O(g)?186views
- Multiple ChoiceWhich thermodynamic property is commonly listed in tables of pure substances and represents the amount of heat required to raise the temperature of one mole of a substance by one degree Celsius at constant pressure?22views
- Multiple Choice
Nitromethane (CH3NO2), sometimes used as a fuel for drag racing, burns according to the following reaction:
4 CH3NO2 (l) + 7 O2 (g) → 4 CO2 (g) + 6 H2O (g) + 4 NO2 (g) ∆Hº = – 2441.6 kJ
How much heat is released by burning 125.0 g of nitromethane (MW:61.044 g/mol)?
3683views8rank1comments - Multiple Choice
Consider the following reaction:
2 C6H6 (l) + 15 O2 (g) → 12 CO2 (g) + 6 H2O (g) ∆Hº = – 6278 kJ
What volume of benzene (C6H6, d = 0.880 g/mL, molar mass = 78.11 g/mol) is necessary to evolve 5.19 x 109 kJ of heat?
2249views4rank - Multiple Choice
The creation of liquid methanol is accomplished by the hydrogenation of carbon monoxide:
CO (g) + 2 H2 (g) → CH3OH (l) ∆Hº = – 128.1 kJ
How much heat (in kJ) is released when 125.0 g CO reacts with 2.32 x 102 g H2?
4217views8rank1comments - Multiple ChoiceConsider two identical iron nails: One nail is heated to 95℃, the other is cooled to 15℃. The two nails are placed in a coffee cup calorimeter and the system is allowed to come to thermal equilibrium. What is the final temperature of the two nails?674views
- Open Question
Which answer best describes the transfer of heat that occurs when 1.50 mol of H2 reacts?
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