The reaction that was on the screen when you started and its derivative demonstrate that the reaction enthalpy, ΔH, changes sign when a process is reversed. Consider the reaction H2O(l)→H2O(g), ΔH =44.0kJ What will ΔH be for the reaction if it is reversed?

2 K2O(s) + O2(g) → 2 K2O2(s) ΔH = -265 kJ8 KO2(s) → 4 K2O(s) + 6 O2(g) ΔH = +832 kJ4 KO2(s) → 2 K2O2(s) + 2 O2(g) ΔH = +146 kJWhat is the ΔH for the over all reaction in kJ/mol?8K2O(s) + 6O2(g) → 6 K2O2(s) + 4 KO2(s)

4. Laboratory quantities of ethylene gas, C2HA(g), can be prepared by an elimination reaction of ethanol using an acid catalyst. What mass ethylene would have been produeced if 5.00kg of air in the surroundings changed from 25.00°C to 19.50°C. Assume that energy transfer is only occurring with the air and that the air has an average molar mass of 29.0g/mol. C2H$OH(I) → C,Ha(g) + H20(1) AH° = ?

Measurements show that the enthalpy of a mixture of gaseous reactants increases by 238. kJ during a certain chemical reaction, which is carried out at a constant pressure. Furthermore, by carefully monitoring the volume change it is determined that 197. kJ of work is done on the mixture during the reaction 1. Calculate the change in energy of the gas mixture during the reaction. Round your answer to 3 significant digits.2. Is the reaction exothermic or endothermic?

Consider the equilibrium reaction of CO (g) with H2 (g) to form CH3OH (g). For this reaction, ΔH < 0.   What is the best way to manipulate this exothermic reaction to produce more CH3OH (g)?

Determine the enthalpy of reaction for HCI(g) + NaNO2(s) -> HNO2 (l) + NaCl(s) 2NaCl(s) + H2O(l) → 2HCI(g) + Na2O(s) ∆H ° =-507.1 kJ/mol NO(g) + NO2(g) + Na2O(s)→ 2N2NO2 (s) ∆H ° = -427.0 kJ/mol NO (g) + NO2 (g) -> N2O(g) + O2 (g) ∆H ° =-43.01 kJ/mol 2HNO2 (l) -> N2O (g) + O2 (g) + H2O(l) ∆H ° = +34.02 kJ/mol

A student dissolves 11.4 g of sodium hydroxide (NaOH)in 200. g of water in a well-insulated open cup. She then observes the temperature of the water rise from 20.0 °C to 35.7 °C over the course of 3.7 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: NaOH (s) Na(aq) + OH (aq) You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to 3 significant digits. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction. Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. Calculate the reaction enthalpy ΔΗ per mole of NaOH. rxn exothermic…

3. A student added calcium to water and measured the increase in temperature to determine AH for the redox reaction: Ca(s) + H₂O(l) → Ca(OH)₂(aq) + H₂(g). When 0.6418 g Ca was added to 200.0 mL of distilled water in a styrofoam cup, the change in temperature was +8.4°C. The density of the water was 1.00 g/mL. a. Which element is being oxidized in this reaction? Which is reduced? b. Calculate the Joules of energy absorbed by the calorimeter, given that Ccal = 20. J/°C. C. Calculate the Joules of energy absorbed by the solution, given that Ssoln = 4.184 J/g°C. [Note that msoln is the combined weight of water and calcium dissolved into water] d. Calculate the Joules of energy released by the reaction. Calculate the enthalpy of reaction, per gram of calcium. f. Calculate the enthalpy of reaction, per mole of calcium. e.

A student dissolves 14.1 g of sodium hydroxide (NaOH)in 250. g of water in a well-insulated open cup. He then observes the temperature of the water rise from 22.0 °C to 35.5 °C over the course of 6.5 minutes. Use this data, and any information you need from the ALEKS Data resource, to answer the questions below about this reaction: NaOH(s) Na+ (aq) + OH (aq) You can make any reasonable assumptions about the physical properties of the solution. Be sure answers you calculate using measured data are rounded to 3 significant digits. Note for advanced students: it's possible the student did not do the experiment carefully, and the values you calculate may not be the same as the known and published values for this reaction. Is this reaction exothermic, endothermic, or neither? If you said the reaction was exothermic or endothermic, calculate the amount of heat that was released or absorbed by the reaction in this case. Calculate the reaction enthalpy AHxn per mole of NaOH. exothermic O…

A chemist measures the enthalpy change AH during the following reaction: 2H,0(1) + O,(g)→2H,O2(1) AH=196. kJ Use this information to complete the table below. Round each of your answers to the nearest kJ/mo reaction ΔΗ x10 6H,0,(1) → 6H,0(1) + 30,(g) 4H,0(1) + 20,(g) → 4H,0,(1) I kJ 2H,0,(1) → 2H,0(1) + 0,(g) kJ