A scientist mixed 25.00 mL of 2.00 M KOH with 25.00 mL of 2.00 M HBr. The temperature of the mixed solution rose from 22.7 oC to 31.9 oC. Calculate the enthalpy change for the reaction in kJ/mol HBr, assuming that the calorimeter loses negligible heat, that the volumes are additive, and that the solution density is 1.00 g/mL, and that its specific heat is 4.184 J/g. oC.

38.493 KJ/mol

Explanation:

Equation of reaction; HBr + KOH ---> KBr + H2O

Heat evolved = mass * specific heat capacity * temperature rise

Mass of solution = density * volume

Mass = 1.00 g/ml*50 ml = 50g

Temperature rise = 31.9 - 22.7 = 9.2 °C

Heat evolved = 50 * 4.184 * 9.2 = 1924.64 J

From the equation of reaction, 1 mole of HBr reacts with 1mole of KOH to produce 1 mole of H20

Number of moles of HBr involved in the reaction = molar concentration * volume (L)

Molar concentration = 2.0 M, volume = 25 ml = 0.025 L

Number of moles = 2.0 M * 0.025 L= 0.05 moles

Therefore, 0.05 moles of HBr reacts with 0.05 moles of KOH to produce 0.05 moles of H20

Enthalpy change per mole of HBr = 1924.64 J/0.05 moles = 38492.8 J/mol = 38.493 KJ/mol

hurricanes form when warm, moist air from the ocean surface quickly rises into the atmosphere and forms storm clouds and rain. when the clouds are formed, heat is released which warms the cool air in the upper regions of the atmosphere so that the cycle can continue. which two phases of the water cycle are repeated in this process?

a corroding iron, if that's one of your choices