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Given the following thermochemical equations.
determine the enthalpy change for the reaction
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Chapter 10 Solutions
Chemistry: Atoms First
- Given the following thermochemical equations: 4B(s)+3O2(g)2B2O3(s)H=2543.8kJ H2(g)+12 O2(g)H2O(g)H=241.8kJ B2H6(s)+3O2B2O3(s)+3H2O(g)H=2032.9kJ Calculate H for the decomposition of B2H6 into its elements.arrow_forwardWhen solid iron burns in oxygen gas (at constant pressure) to produce Fe2O3(s), 1651 kJ of heat is released for every 4 mol of iron burned. How much heat is released when 10.3 g Fe2O3(s) is produced (at constant pressure)? What additional information would you need to calculate the heat released to produce this much Fe2O3(s) if you burned iron in ozone gas, O3(g), instead of O2(g)?arrow_forwardAcetic acid, HC2H3O2, is the sour constituent of vinegar (acetum is Latin for vinegar). In an experiment, 3.58 g of acetic acid was burned. HC2H3O2(l)+2O2(g)2CO2(g)+2H2O(l) If 52.0 kJ of heat evolved, what is H per mole of acetic acid?arrow_forward
- Determine whether the statements given below are true or false. Consider an endothermic process taking place in a beaker at room temperature. (a) Heat flows from the surroundings to the system. (b) The beaker is cold to the touch. (c) The pressure of the system decreases. (d) The value of q for the system is positive.arrow_forwardGiven the following (hypothetical) thermochemical equations: A+B2C;H=447kJA+3D2E;H=484kJ2D+B2F;H=429kJ Calculate H, in kJ, for the equation 4E+5B4C+6Farrow_forwardA sample of sucrose, C12H22O11, is contaminated by sodium chloride. When the contaminated sample is burned in a bomb calorimeter, sodium chloride does not burn. What is the percentage of sucrose in the sample if a temperature increase of 1.67C is observed when 3.000 g of the sample are burned in the calorimeter? Sucrose gives off 5.64103kJ/mol when burned. The heat capacity of the calorimeter and water is 22.51 kJ/C.arrow_forward
- The temperature of the cooling water as it leaves the hot engine of an automobile is 240 F. After it passes through the radiator it has a temperature of 175 F. Calculate the amount of heat transferred from the engine to the surroundings by one gallon of water with a specific heat of 4.184 J/g oC.arrow_forwardAn industrial process for manufacturing sulfuric acid, H2SO4, uses hydrogen sulfide, H2S, from the purification of natural gas. In the first step of this process, the hydrogen sulfide is burned to obtain sulfur dioxide, SO2. 2H2S(g)+3O2(g)2H2O(l)+2SO2(g);H=1124kJ The density of sulfur dioxide at 25C and 1.00 atm is 2.62 g/L, and the molar heat capacity is 30.2 J/(mol C). (a) How much heat would be evolved in producing 1.00 L of SO2 at 25C and 1.00 atm? (b) Suppose heat from this reaction is used to heat 1.00 L of the SO2 from 25C to 500C for its use in the next step of the process. What percentage of the heat evolved is required for this?arrow_forwardNatural gas companies in the United States use the therm as a unit of energy. One therm is 1105 BTU. (a) How many joules are in one therm? (1J=9.48104BTU) (b) When propane gas, C3H8, is burned in oxygen, CO2 and steam are produced. How many therms of energy are given off by 1.00 mol of propane gas?arrow_forward
- A compound is 82.7% carbon and 17.3% hydrogen, and has a molar mass of approximately 60 g/mol. When 1.000 g of this compound burns in excess oxygen, the enthalpy change is 49.53 kJ. (a) What is the empirical formula of this compound? (b) What is the molecular formula of this compound? (c) What is the standard enthalpy of formation of this compound? (d) Two compounds that have this molecular formula appear in Appendix G. Which one was used in this exercise?arrow_forwardCalcium carbide, CaC2, is manufactured by reducing lime with carbon at high temperature. (The carbide is used in turn to make acetylene, an industrially important organic chemical.) Is the reaction endothermic or exothermic?arrow_forwardSulfur dioxide gas reacts with oxygen, O2(g), to produce SO3(g). This reaction releases 99.0 kJ of heat (at constant pressure) for each mole of sulfur dioxide that reacts. Write the thermochemical equation for the reaction of 2 mol of sulfur dioxide, and then also for the decomposition of 3 mol of sulfur trioxide gas into oxygen gas and sulfur dioxide gas. Do you need any other information to answer either question?arrow_forward
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