Estimate the enthalpy of vaporization of water at 92.5 °C from its value at 25 °C (44.01 kJ mol−1), given the constant-pressure heat capacities of 75.29 J K−1mol−1 and 33.58 J K−1 mol− 1 for liquid and gas, respectively. ______ kJ/mol. 4 sig. number

A quantity of 2.00×102 mL of 0.786 M HCl is mixed with 2.00×102 mL of 0.393 M Ba(OH)2 in a constant-pressure calorimeter of negligible heat capacity. The initial temperature of the HCl and Ba(OH)2 solutions is the same at 20.76°C. For the process below, the heat of neutralization is −56.2 kJ/mol. What is the final temperature of the mixed solutions?   H+(aq) + OH−(aq)→H2O(l)   _____°C

A constant pressure calorimeter contains 286 g of water at 20.0 °C. A 13.41 g of substance X (molar mass 154 g/mol) at 20.0°C was dissolved in this water.  The temperature of the solution increased to 23.5 °C. Assuming the specific heat of the mixture is 4.184 J g‑1°C‑1, and the density of the solution is 1.00 g/cm3, calculate the enthalpy change (in kJ) for the dissolution of 1 mole of X.

Potassium nitrate, KNO3, has a molar mass of 101.1 g/mol. In a constant-pressure calorimeter, 48.1 g of KNO3KNO3 is dissolved in 229 g of water at 23.00 °C.   KNO3(s)−→−−H2OK+(aq)+NO−3(aq)   The temperature of the resulting solution decreases to 17.80 °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? ?soln=   kJ What is the enthalpy of the reaction? Δ?rxn=   kJ/mol

Measurements show that the energy of a mixture of gaseous reactants increases by 178. 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 - 143. kJ of work is done on the mixture during the reaction. Calculate the change in enthalpy of the gas mixture | kJ during the reaction. Round your answer to 3 significant digits. x10 ? exothermic Is the reaction exothermic or endothermic? endothermic

When a 6.00 g6.00 g sample of KClKCl is dissolved in water in a calorimeter that has a total heat capacity of 4.47 kJ⋅K−1,4.47 kJ⋅K−1, the temperature decreases by 0.310 K.0.310 K. Calculate the molar heat of solution of KCl.

using a calibrated solution calorimeter measured a temperature decrease of 1.10 K when 1.00 g of KNO3 was added to 74.40 g of deionized water in the calorimeter. The specific heat capacity of the solution calorimeter was found to be 4.15 J/gK. Calculate the experimental value of the molar heat of solution of KNO3, ΔHsoln. Was the dissolution of this salt exothermic or endothermic?

Calculate the heat of neutralization (kJ/mole) for the reaction of 50.0 mL of 0.177 M potassium hydroxide with 100.0 mL 0.841 M sulfuric acid resulting in a temperature increase of 4.61 oC.  Assume the solutions have a density of water and specific heat capacity of water, 4.184 J/(g⋅oC).  The calorimeter is a perfect system with no heat loss.   2KOH + H2SO4 ⟶ K2SO4 + 2H2O Group of answer choices +34.4 kJ/mole -218 kJ/mole -34.4 kJ/mole +218 kJ/mole -2890 kJ/mole +654 kJ/mole -654 kJ/mole +2890 kJ/mole +109 kJ/mole -327 kJ/mole +327 kJ/mole -109 kJ/mole

Measurements show that the enthalpy of a mixture of gaseous reactants decreases by 253. 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 149. kJ of work is done on the mixture during the reaction. Calculate the change in energy of the gas mixture during the reaction. Round your answer to 3 |kJ х10 significant digits. exothermic Is the reaction exothermic or endothermic? endothermic

4.00 g NaOH(s) (39.996 g mol–1) dissolves in 100.0 g of water in a constant–pressure calorimeter. The initial temperatures of both materials are the same at 20.0°C. The density of the solution is 1.00 g cm–3. The heat of dissolution is –44.51 kJ mol–1. The specific heat of the solution is 4.184 J g–1 °C–1. The specific heat of the calorimeter is 100 J °C–1. What is the final temperature of the solution?   30.23°C   25.94°C   28.32°C What is the energy lost to the calorimeter?   579 J   832 J   721 J