Exam 6: Thermochemistry

A bomb calorimeter has a heat capacity of 2.47 kJ/K.When a 0.106-g sample of a certain hydrocarbon was burned in this calorimeter,the temperature increased by 2.14 K.Calculate the energy of combustion for 1 g of the hydrocarbon.

Which of the following is not a fuel-oxidizer mixture used in rockets?

Which of the following is an endothermic process?

A 86.9-g sample of chromium (s = 0.447 J/(g ∙ °C)),initially at 338.33°C,is added to an insulated vessel containing 189.9 g of water (s = 4.18 J/(g ∙ °C)),initially at 16.17°C.At equilibrium,the final temperature of the metal-water mixture is 28.06°C.How much heat was absorbed by the water? The heat capacity of the vessel is 0.220 kJ/°C.

Given: what is ΔH for the following thermochemical equation?

Which of the following sentences accurately describes the thermochemical equation given below? 2Ag(s)+ F₂(g)→ 2AgF(s); ΔH = -409.2 kJ

How much heat is released at constant pressure if 12.3 mL of 0.161 M silver nitrate is mixed with 41.7 mL of 0.493 M potassium chloride? AgNO₃(aq)+ KCl(aq)→ AgCl(s)+ KNO₃(aq); ΔH° = -65.5 kJ

Which of the following statements is true concerning the decomposition of liquid water to form hydrogen gas and oxygen gas? 2H₂O(l)→ 2H₂(g)+ O₂(g)

The energy associated with an object held above the surface of the earth is called _____.

A 3.540-g sample of an unknown metal M is burned in the presence of excess oxygen,producing the oxide M₂O₃(s)and liberating 18.56 kJ of heat at constant pressure.What is the identity of the metal? 4M(s)+ 3O₂(g)→ 2M₂O₃(s) Substance ΔH°_f (kJ/mol) Yb₂O₃(s) -1814.6 Tb₂O₃(s) -1865.2 Sm₂O₃(s) -1823.0 Sc₂O₃(s) -1908.8 Y₂O₃(s) -1905.3

What is the change in enthalpy at 25°C and 1 atm for the production of 3.00 mol SnO(s)? Sn(s)+ SnO₂(s)→ 2SnO(s); ΔH° = 16.2 kJ

Given the following thermochemical data at 25°C and 1 atm pressure, O₂(g)+ 2B(s)→ B₂O₃(s); ΔH° = -1264 kJ O₃(g)+ 2B(s)→ B₂O₃(s); ΔH° = -1406 kJ Determine ΔH° for the following reaction at 25°C and 1 atm pressure. 3O₂(g)→ 2O₃(g)

When 56.8 g of lead reacts with 3.50 L of oxygen gas,measured at 1.00 atm and 25.0°C,60.1 kJ of heat is released at constant pressure.What is ΔH° for this reaction? (R = 0.0821 L • atm/(K • mol)) 2Pb(s)+ O₂(g)→ 2PbO(s)

In a certain experiment,0.7000 mol of hydrogen gas reacted with 0.7000 mol of solid iodine at a constant 1 atm pressure,producing 1.4000 mol of solid hydrogen iodide and absorbing 36.9 kJ of heat in the process.Which of the following thermochemical equations correctly describes this experiment?

Which of the following has a standard enthalpy of formation value of zero at 25°C?

What is ΔH° of the following reaction? CO₂(g)+ 2CH₄(g)→ C₃H₈(g)+ O₂(g) Substance ΔH°_f (kJ/mol) CO₂(g) -393.5 CH₄(g) -74)9 C₃H₈(g) -104.7

Given that O(g)+ e^- → O^-(g); ΔH = -142 kJ O(g)+ 2e^- → O^2-(g); ΔH = 702 kJ The enthalpy change for the reaction represented by the equation O^-(g)+ e^- → O^2-(g)is

A 84.8-g piece of silver (s = 0.237 J/(g ∙ °C)),initially at 268.0°C,is added to 128.4 g of a liquid,initially at 24.9°C,in an insulated container.The final temperature of the metal-liquid mixture at equilibrium is 39.6°C.What is the identity of the liquid? Neglect the heat capacity of the container.

The units for specific heat are