Enthalpy Change of a Reaction (ΔrH) - Standard Enthalpy of Reactions

The value of ∆_fH^Θ for \[\ce{NH3}\] is – 91.8 kJ mol^–1. Calculate enthalpy change for the following reaction:

\[\ce{2NH3(g) -> N2(g) + 3H2(g)}\]

18.0 g of water completely vapourises at 100°C and 1 bar pressure and the enthalpy change in the process is 40.79 kJ mol–1. What will be the enthalpy change for vapourising two moles of water under the same conditions? What is the standard enthalphy of vapourisation for water?

Given

\[\ce{N_{2(g)} + 3H_{2(g)} -> 2NH_{3(g)}}\]; Δ_rH^θ = –92.4 kJ mol^–1

What is the standard enthalpy of formation of NH₃ gas?

Enthalpy of combustion of carbon to CO₂ is –393.5 kJ mol^–1. Calculate the heat released upon formation of 35.2 g of CO₂ from carbon and dioxygen gas.

The enthalpies of all elements in their standard states are ______.

The reaction of cyanamide, NH₂CN_(s), with dioxygen was carried out in a bomb calorimeter, and ΔU was found to be −742.7 kJ mol⁻¹ at 298 K. Calculate enthalpy change for the reaction at 298 K.

\[\ce{NH_2 CN(g) + 3/2 O_2(g) -> N_2(g) + CO_2(g) + H_2O(l)}\]

Calculate the entropy change in surroundings when 1.00 mol of H₂O_(l) is formed under standard conditions. Δ_fH^θ = –286 kJ mol^–1.

Calculate the enthalpy change on freezing of 1.0 mol of water at 10.0°C to ice at - 10.0°C. Δ_fusH = 6.03 kJ mol^-1 at 0°C.

C_p[H₂O(l)] = 75.3 J mol^-1 K^-1

C_p[H₂O(s)] = 36.8 J mol^-1 K^-1