Given the following thermochemical equations, 4B(s) + 3O2(g) → 2B2O3(s)                         ∆Ho= -2543.8 kJ H2 (g) + ½ O2(g) → H2O (g)                        ∆Ho= -241.8 kJ B2H6(s) + 3O2(g) → B2O3(s) + 3H2O (g)   ∆Ho= -2032.9 kJ Which equation shows the decomposition of B2H6 into its elements?     B2H6(s)  → 2B (s) + 3H2 (g)     B2H6(s) + 3O2(g) → B2O3(s) + 3H2O (g)     2B2O3(s)   →  4B(s) + 3O2(g)     B2H6(s) + 3O2(g) → B2O3(s) + 3H2O (g)

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.88 kg sample of C,H0, from 35.8 °C to 51.4 °C. The experiment shows that 2.34 × 10* J of heat are needed. What can the chemist report for the molar heat capacity of C,H00,? Round your answer to 2 significant digits. |J-mol 1 - 1 •K х10

A 0.870-g piece of lithium metal is dropped into a mixture of 50.0 g water and 50.0 g ice, both at 0°C. The reaction is 2 Li(s) + 2 H₂O(l) → 2 LiOH(aq) + H₂(g) ∆H = 446 kJ/mol Assuming no heat is lost to the surroundings, and that the final mixture has a specific heat capacity of 4.18 J/g･°C, calculate the final temperature in °C. The enthalpy of fusion for ice is 6.02 kJ/mol.

The molar heat capacity of silver is 25.35 J/mol⋅∘C . How much energy would it take to raise the temperature of 8.60 g of silver by 14.4 ∘C?

Given the thermochemical equation for photosynthesis, 6H2O(l) + 6CO2(g) → C6H12O6(s) + 6CO2(g)  ∆H = +2803 kJ/mol calculate the solar energy required to produce 100.0 g of C6H12O6

A 56.5 g sample of iron is put into a calorimeter (see sketch at right) that contains 300.0 g of water. The iron sample starts off at 86.7 °C and the temperature of the water starts off at 21.0 °C. When the temperature of the water stops changing it's 22.8 °C. The pressure remains constant at 1 atm. Calculate the specific heat capacity of iron according to this experiment. Be sure your answer is rounded to 2 significant digits. J 0₂-C x10 x thermometer insulated container water sample a calorimeter

a You want to determine the value for the enthalpy of formation of CaSO4(s). Ca(s) + S(s) + 2 O₂ (g) → CaSO4(s) This reaction cannot be done directly. You know, however, that both calcium and sulfur react with oxygen to produce oxides in reactions that can be studied calorimetrically. You also know that the basic oxide CaO reacts with the acidic oxide SO3 (g) to produce CaSO4(s) with A₁ H° = -402.7 kJ. Outline a method for determining A₁H˚ for CaSO4(s), and identify the information that must be collected by experiment. Using enthalpy of formation data, confirm that AƒH° for CaSO4(s) = −1433.5 kJ/mol. What compound is formed when Ca and O2 react?

A chemist carefully measures the amount of heat needed to raise the temperature of a 531.0mg sample of C9H10O2 from 40.1°C to 58.2°C . The experiment shows that 15.1J of heat are needed. What can the chemist report for the molar heat capacity of C9H10O2 ? Be sure your answer has the correct number of significant digits. ⋅J⋅mol−1K−1

Using the following thermochemical data: 2Er(s) + 6HF(g) → 2ErF3(s) + 3H2(g) ΔH° = -1795.4 kJ/mol 2Er(s) + 6HCl(g) → 2ErCl3(s) + 3H2(g) ΔH° = -1443.6 kJ/mol calculate ΔH° for the following reaction:ErF3(s) + 3HCl(g) → ErCl3(s) + 3HF(g) 351.8 kJ/mol -3239.0 kJ/mol -1619.5 kJ/mol 703.6 kJ/mol 175.9 kJ/mol

Hot water heaters often use natural gas (methane) to generate heat. Methane and oxygen react to form carbon monoxide according to the overall equation: 2CH4(g)+3O2(g) = 2CO(g)+4H2O(g) The enthalpy of formation for each compound are as follows: CH4: - 74.6 O2: 0 CO: - 110.5 H2O: - 285.8 Part A: calculate the overall enthalpy change of the reaction. Part B: A typical water heater contains 40.0 gallons of water. After a long vacation, you come home and turn your water heater from "vacation mode" to hot. How many moles of methane must be combusted to heat the water in your water heater from 30.0°C to 48.0°C? The density of water is 3.79 kg/gal, the specific heat capacity of water is 4.182 J/g°C, and the water heater has a heat capacity of 850.0 J/g°C.