How much heat is produced by combustion of 25.0 g of ethanol under standard state conditions? C2H5OH(l) + 3O2(g) ⟶ 2CO2(g) + 3H2O(g)        Δ  = −1366.8.1 kJ

6 8 7. Consider the following reaction: 2 CH;OH (g) → 2 CH4() O2 (g), AH = + 252.8 kJ a) Is this reaction exothermic or endothermic? b) Calculate the amount of heat transferred when 26.0 g of CH3OH(g) is decomposed by this reaction at constant pressure. Express the heat to three significant digits with the appropriate units. c) For a given sample of CH;OH, the enthalpy change during the reaction is 82.9 kJ. What mass of methane gas is produced? Express the mass to three significant digits with the appropriate units. d) How many kilojoules of heat are released when 38.8 g CH4(g) reacts completely with 02(g) to form CH,OH(g) at constant pressure?

Potassium nitrate, KNO 3, has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 41.8 g of KNO3 is dissolved in 277 g of water at 23.00 °C. KNO3(s) H₂O K+(aq) + NO3(aq) The temperature of the resulting solution decreases to 20.90 °C. Assume that the resulting solution has the same specific heat as • water, 4.184 J/(g · °C), and that there is negligible heat loss to the surroundings. How much heat was released by the solution? Isoln = What is the enthalpy of the reaction? AH rxn = KJ kJ/mol

4 Fe(s) + 3 O2(g) → 2 Fe2O3(s), ΔH = -1652 kJ (a) How much heat is released when 4.47 mol iron is reacted with excess O2?

A chemist carefully measures the amount of heat needed to raise the temperature of a 0.81kg sample of C4H6O2 from 31.4c to 49.6c. The experiment shows that 2.48*10^4 J of heat are needed. what can the chemist report for the molar heat capacity of C4H6O2 ? Round your answer to 2 sig figs.

How many moles of butane, C4H10(l), must be burned to produce 234 kJ of heat under standard state conditions? (The heat of combustion for butane is −2855.7 kJ/mol.)

Use the following information to calculate the amount of heat involved in the complete reaction of 7.20 g of carbon to form PbCO3(s) in reaction 4. Be sure to give the proper sign (positive or negative) with your answer. Reaction 1 Pb(s) + O₂(g) PbO(s) Reaction 2 C(s,graphite) + O₂(g) →→→ CO₂(g) Reaction 3 PbCO3(s). PbO(s) + CO₂(g) Reaction 4 Pb(s) + C(s,graphite) + O₂(g) →→→ PbCO3(s) 1st attempt AH rxn4° = ? kJ AH rxnl AHO rxn2 AHO rxn3 AHXn4 = -219 kJ = - 394 kJ = 86 kJ = ? See Periodic Table See Hint

What is the enthalpy change when 47.6 g Al completely react, given the reaction below?   The molar mass of Al = 27.0 g/mol.  Fe2O3(s) + 2 Al(s) → Al2O3(s) + 2 Fe(s)        ΔH°rxn = -852 kJ

The standard enthalpy change for the following reaction is -135 kJ at 298 K. 1/2 N2(g) + 1/2 H2(g) + 3/2 O2(g) HNO3(g)       ΔH° = -135 kJ What is the standard enthalpy change for the reaction at 298 K? N2(g) + H2(g) + 3 O2(g)2 HNO3(g) kJ

In a constant‑pressure calorimeter, 60.0 mL of 0.320 M Ba(OH)2 was added to 60.0 mL of 0.640 M HCl.The reaction caused the temperature of the solution to rise from 24.50 ∘C to 28.86 ∘C. If the solution has the same density and specific heat as water (1.00 g/mLand 4.184J/g⋅°C, respectively), what is ΔH for this reaction (per mole H2O produced)? Assume that the total volume is the sum of the individual volumes. ΔH= _________ kJ/mol H2O