Label each of the following reactions as exothermic or endothermic ("exo" or "endo"), and according to whether work is done on or by the system, or no work is done at all ("on", "by" or "none")? Note that no "endo-on" cases appear here, as these are always thermodynamically unfavourable. There is no need to do any calculation, use chemical arguments to predict the sign of the enthalpy change. Options: exo-on, exo-by, endo-by, exo-none  NH3(g) + HCl(g) --> NH 4 Cl(s) Cl2(aq) + 2 KBr(aq) --> 2 KCl(aq)+Br 2 (aq) N2 (l)--> N2 (g) S(s)+3/2 O 2 (g) --> SO3 (g) Zn(s) + 2HCl(aq) --> ZnCl 2 (aq)+H 2 (g)

Consider the two reactions. 2 NH, (g) + 3 N,0(g) → 4N,(g) + 3 H,0(1) 4 NH, (g) + 3 0,(g) 2 N,(g) + 6 H,0(1) AH° = -1010 kJ AH° = 1531 kJ Using these two reactions, calculate and enter the enthalpy change for the reaction below. N, (g) + 0,(g) → N,0(g)

From the enthalpies of reaction 2C(s) + O2 (9) → 2C0(g) 2C(s) + O2 (9) + 4H2 (g) → 2CH3 OH(g) AH ΔΗ :-221.0kJ %3| :-402.4kJ calculate AH for the reaction CO(g) + 2H2 (g) → CH3 OH(g) Express your answer to three significant figures with the appropriate units.

1,2,3 please

O-234 kJ 234 kJ -150. kJ -117 kJ Given: -1835kJ AH°, AHᵒf (kJ/mol) -941 -840 QUESTION 12 Use the standard reaction enthalpies given below to determine AH°rxn for the following reaction: P4(g) + 10 Cl₂(g) → 4 PC|5(s) PC15(s) → PC13(g) + Cl₂(g) P4(g) + 6 Cl₂(g) → 4 PCl3(g) rxn IF7(g) IF 5(9) 2(g) 62.42 = ? ΔΗ° rxn AH°rxn = +157 kJ = -1207 KJ QUESTION 13 Use the AH°f and AH°rxn information provided to calculate AH°f for IF: IF7(9) + 12(g) → IF5(g) + 2 IF(g) AH°rxn = -89 kJ

Which statement best aligns with one of the three laws of thermodynamics? O AG--T(AS+AS) O AG-AU-PAV-TAS O AG-TAS O AG-T(AS-AS)

Enthalpy and Gibb's Free Energy Chemical energy is released or absorbed from reactions in various forms. The most easily measurable form of energy comes in the form of heat, or enthalpy. The enthalpy of a reaction can be calculated from the heats of formation of the substances involved in the reaction: AHxn = AH₂ (products) - AH (reactants) Entropy change, AS°, is a measure of the number of energetically equivalent microstates introduced into the system during the reaction. The degree of spontaneity of a reaction is represented by the Gibbs free energy, AGO. The Gibbs free energy depends on both the enthalpy and entropy changes that take place during the reaction: AG=AH° - TAS° where T is standard temperature, 298 K. ▼ Part A Calculate the standard enthalpy change for the reaction where the heats of formation are given in the following table: ΔΗ Substance (kJ/mol) A B C D -241 -407 191 -501 Express your answer in kilojoules. ► View Available Hint(s) {—| ΑΣΦ AHixn= 2A+B=2C+2D ? kJ…

1. A 50g sample of metal iron that was heated to 90 °C was dropped into a coffee cup calorimeter containing 200mL of water at room temperature of 25 °C. Applying the density of water (1g/mL) and specific heat capacity capacities of water and iron, determine the final temperature when the system reaches equilibrium.