Dimethyl ether, a useful organic solvent, is prepared in two steps. In the first step, carbon dioxide and hydrogen react to form methanol and water: CO₂(g) + 3 H₂(g) → CH₂OH(1) + H₂O(1) In the second step, methanol reacts to form dimethyl ether and water: 2 CH3OH(1)→ CH3OCH3(g) + H₂O(1) ΔΗ= 8. kJ ΔΗ=-131. kJ Calculate the net change in enthalpy for the formation of one mole of dimethyl ether from carbon dioxide and hydrogen from these reactions. Round your answer to the nearest kJ.

A chemist carefully measures the amount of heat needed to raise the temperature of a 1.85 kg sample of C,H,,S from -0.2 °C to 10.8 °C. The experiment shows that 4.04 × 10" J of heat are needed. What can the chemist report for the molar heat capacity of C,H,S? Round your answer to 3 12 significant digits. |J•mol 1 ·K x10 ?

Please answer both questions

Calculate the standard enthalpy for the reaction: 4NH3(g) + 5O2(g) → 4NO(g) + 6H2O(g), given the following data: N2(g) + O2(g) → 2NO(g) ΔHrxn = -43.1 kcal mol-1   N2(g) + 3H2(g) → 2NH3(g) ΔHrxn = -21.9 kcal mol-1   2H2(g) + O2(g) → 2H2O(g) ΔHrxn = -115.6 kcal mol-1   Round your answer to 2 decimal places.

A chemist measures the enthalpy change AH during the following reaction: 2 Al(OH)3(s)→Al,03(s) + 3 H,0(1) AH=41. kJ Use this information to complete the table below. Round each of your answers to the nearest kJ/mol. reaction ΔΗ x10 2 Al,0, (s) + H,0(1) Al(OH), (s) kJ 3 3 Al, O, (s) + 3H,0(1) → 2A1(OH), (s) kJ 3 Al(OH), (s) → Al, 0, (s) + H,0() |kJ 3

3

The reaction between sodium metal and chlorine gas produces 822 kJ of heat energy for every chlorine molecule consumed [2 Na(s) + Cl2(g) → 2 NaCl(s)]. How much heat is released (in kJ) if 1.569 g of Na are consumed in the reaction?

Consider the following reaction. (a) Is the reaction exothermic or endothermic? exothermic endothermic CH3OH(g) → CO(g) + 2 H₂(g) AH +90.7 kJ (b) Calculate the amount of heat transferred when 35.0 g of CH3OH(g) are decomposed by this reaction at constant pressure. ΔΗ= 100.8 (c) If the enthalpy change is 19.0 kJ, how many grams of hydrogen gas are produced? 0.42 x g (d) How many kilojoules of heat are released when 13.0 g of CO(g) reacts completely with H₂(g) to form CH₂OH(g) at constant pressure? AH = -90.7 X kJ (e) Calculate AE when 400.0 g of CH3OH(g) completely reacts at a constant temperature of 300 K and constant pressure of 0.95 atm. R = 8.314 J/mol*K and R = 0.08206 atm*L/mol K-41.7 XkJ HopHelpCh5N1

The standard enthalpy of formation of NiSO 4(s) at 25 °C is -872.9 kJ/mole. The chemical equation to which this value       Ni(s) + S(s) + 2 O2(g) → NiSO4(s)     1/2 Ni(s) + 1/2 S(s) + 1/2 O2(g) → 1/2 NiSO4(s)     NiSO4(s) → Ni(s) + S(s) + 4 O(g)     Ni(s) + S(s) + 4 O(g) → NiSO4(s)

Consider these reactions, where M represents a generic metal. 1. 2 M(s) + 6 HCI(aq) → 2 MCl, (aq) + 3 H, (g) AH1 = -789.0 kJ 2. HCl(g) HCl(aq) ΔΗ = -74.8 kJ 3. H, (g) + Cl, (g) → 2 HCl(g) AH3 = -1845.0 kJ 4. MCI, (s) → MCl, (aq) ΔΗ4 = -418.0 kJ Use the given information to determine the enthalpy of the reaction 2 M(s) + 3 Cl, (g) → 2 MCI, (s)