You are given the following hypothetical reactions: 2A → B+C ΔΗ = +50 kJ A → D AH = -80 kJ Part A Use Hess's law to calculate AH for the reaction B + C → 2D. Express your answer in kilojoules to three significant figures. 15. ΑΣΦ AH = Submit Part B AH = Request Answer Submit What is AH for the reaction D → 1 2 Express your answer in kilojoules to three significant figures. VGI ΑΣΦ Request Answer B + 1²1/20 ? C? kJ ? kJ

Consider these reactions, where M represents a generic metal. 1. 2 M(s) + 6 HCI(aq) 2 MCI, (aq) + 3 H, (g) ΔΗ = -550.0 kJ 2. HCl(g) HCI(aq) AH2 = -74.8 kJ > 3. H, (g) + Cl, (g) → 2 HCl(g) AH3 = -1845.0 kJ 4. MCl, (s) → MCI, (aq) AH4 = -291.0 kJ Use the given information to determine the enthalpy of the reaction 2 M(s) + 3 Cl, (g) → 2 MCI, (s) ΔΗ kJ

During an experiment a student mixed two chemicals together and noted that the beaker felt warm to the touch after the reaction was complete. In the experiment, the chemicals would be classified as the From this observation, the student concluded that the reaction was A. Which of the following energy pathway diagrams represents the chemical reaction from the student's experiment? Ep (kJ) Select one: OA OB 150 125 100 + and the beaker would be classified as the Reaction Coordinate and that the resulting change in enthalpy (AH) would have a B. 125 E 100 Reaction Coordinate Ep (kJ) 150 ◆ value.

A 4.81 g sample of an unknown salt (MM = 116.82 g/mol) is dissolved in 150.00 g water in a coffee cup calorimeter. Before placing the sample in the water, the temperature of the salt and water is 23.72°C. After the salt has completely dissolved, the temperature of the solution is 28.54°C.   If 3.12 × 10³ J of heat was gained by the solution, what is the total heat for the dissolution reaction of the 4.81 g of salt?   How many moles of the unknown salt were used in the reaction ?     _______ J?

Consider the reaction   2H2+O2⟶2H2OΔ?rxn=−484 kJ Which answer best describes the transfer of heat that occurs when 1.40 mol H2 reacts?   678 kJ absorbed 484 kJ released 339 kJ released 678 kJ released 484 kJ absorbed 339 kJ absorbed

In the following reaction, how many grams of CH3OH are required to produce 1.578 x 10° kJ of heat? 2 CH3OH (1) +3 O2 (g) → 2 CO2 (g) + 4 H2O(g) AH = -1280. kJ/mol Please do not include units in your answer.

Consider these reactions: Reaction 1: H2(g) + Cl2(g) 2HCl(9) AH = -184.6 kJ Reaction 2: 20F2(g) → O2(g) +2F2(g) AH=-49.4 kJ Reaction 3: Na (g) +202 (9) 2NO2(g) AH = +66.4 kJ Use Reaction 1. Determine the mass, in grams, of chlorine gas consumed (with excess H₂) when 1,409.0 kJ of energy is released from the system. Round to the nearest whole number .

Consider these reactions: Reaction 1: H₂(g) + Cl₂ (g) Reaction 2: 20F2 (g) O2(g) +2 F2 (g) AH Reaction 3: N₂(g) + 2O2(g) → 2NO₂(g) AH = +66.4 kJ Use Reaction 1. — → 2HCl(g) AH = -184.6 kJ g = -49.4 kJ Determine the mass, in grams, of chlorine gas consumed (with excess H₂) when 1,959.0 kJ of energy is released from the system. Round to the nearest whole number. Answer: