Calculate the change in enthalpy for the reaction. (Use 1.0 g/mL as the density of the solution and 4.18 J/(g⋅∘C) as the specific heat capacity.) Express the enthalpy change in kilojoules per mole to two significant figures. ΔHrxn = nothing kJ/mol

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Instant cold packs, often used to ice athletic injuries on the field, contain ammonium nitrate and water separated by a thin plastic divider. When the divider is broken, the ammonium nitrate dissolves according to the following endothermic reaction: NH4NO3(s)→NH+4(aq)+NO−3(aq) In order to measure the enthalpy change for this reaction, 1.25 g of NH4NO3 is dissolved in enough water to make 25.0 mL of solution. The initial temperature is 25.8 ∘C and the final temperature (after the solid dissolves) is 21.9 ∘C. Part A Calculate the change in enthalpy for the reaction in kilojoules per mole. (Use 1.0g/mL as the density of the solution and 4.18J/g⋅∘C as the specific heat capacity.) Express your answer to two significant figures and include the appropriate units. ΔHrxn =   ??? kJ/mol

26 kJ / mol

Explanation:

Given that;

The mass of NH₄NO₃ = 1.25 g

Number of moles of NH₄NO₃ = Mass of NH₄NO₃ / Molar Mass of NH₄NO₃

Number of moles of NH₄NO₃= 1.25 g / 80.043 g/mol

Number of moles of NH₄NO₃= 0.016 mol

Volume of solution = 25.0 mL

Density of Solution = 1.0g/mL

Since;

Mass of Solution = Density x Volume

= 1.0g/mL × 25.0mL

= 25 g

Heat Generated (Q)  =

Q= 25g × 4.18 J/g°C x (25.8°C - 21.9°C)

Q =  407.55 J

Q = 407 × 10 ⁻³ kJ

Q = 0.40755 kJ

Δ =

=  

= 25.47 kJ/ mol

~ 26 kJ / mol

Therefore, the change in enthalpy for the reaction in kilojoules per mole = 26 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?