4. Give the thermochemical equation for the decomposition of ammonia, NH3.NH3 (g) —> 3/2 H2 (g)  + 1/2 N2 (g)                    ΔH = 29.61 kJ*3 pointsNH3 (g) —> 3/2 H2 + 1/2 N2 (g) + 29.61 kJNH3 (g) + 29.61 kJ —> 3/2 H2 + 1/2 N2 (g)NH3 (g) —> 3/2 H2 + 1/2 N2 (g) - 29.61 kJNH3 (g) - 29.61 kJ —> 3/2 H2 + 1/2 N2 (g)Is the reaction in no. 4  endothermic or exothermic?*2 pointsendothermicexothermic

. The thermochemical equation showing the formation of ammonia, NH3 from its elements is:N2 (g) + 3 H2 (g) —> 2 NH3 (g)            ΔH = -92 kJThis equation shows that 92 kJ of heat is ____.*2 pointsabsorbed from the surroundings.released to the surroundings.

Two moles of ammonia is introducedi in an evacuated 500 ml vessel at high temperature. The decomposition reaction is : 2NH3 ->N2 +3H2 at the equillibrium NH3 becomes 1 mole then the 'K' would be:

Q2How many moles of ammonia are produced from 0.60 moles of nitrogen? N2 (g) + 3 H2 (g) yields 2 NH3 (g)2 marks0.60.21.20.3

Identify the letter that best completes the statement or answers the question by circling or highlighting the ONE correct letter. (5 marks) 6. A chemical system in which ONLY energy can flow into or out of a system is described as a. a closed system d. a chemical system b. an open system e. none of the above c. an isolated system 7. The decomposition of ammonia into hydrogen and nitrogen gas has a molar enthalpy of reaction of +45.9 kJ/mol of ammonia. Which of the following would be the CORRECT thermochemical equation to represent this reaction. 2NH3(g) N2(g) + 3H2(g) + 45.9 kJ 2NH3(g) + 45.9 kJ N2(g) + 3H2(g) 2NH3(g) N2(g) + 3H2(g) + 91.8 kJ 2NH3(g) + 91.8 kJ N2(g) + 3H2(g) 2NH3(g) N2(g) + 3H2(g) ∆HRx = -45.9 kJ/mol NH3 8. Using the enthalpies of formation, what is the enthalpy change for the following reaction? CO2(g) → CO(g) + 1/2 O2(g) a. –283 kJ d. +506 kJ b. +283 kJ e. None of the above c. -506 kJ 9. Using the following thermochemical data: 1. C2H2(g) + 5/2 O2(g) → 2CO2(g) + H2O(l) ΔH = –1.30 × 103 kJ 2. C2H6(g) + 7/2 O2(g) → 2CO2(g) + 3H2O(l) ΔH = –1.56 × 103 kJ 3. H2(g) + 1/2 O2(g) → H2O(l) ΔH = –2.86 × 102 kJ What is ∆H for the following reaction? C2H6(g) → C2H2(g) + 2H2(g) a. -2.60 x 101 kJ d. -5.46 x 103 kJ b. -3.12 x 102 kJ e. 2.60 x 101 kJ c. +3.12 x 102 kJ f. none of the above 10. For the following reaction, the rate of consumption of Al(s) is -2.0 mol/L s. The rate of production of Na would be: ? a. 2 mol/Ls d. 18 mol/Ls b. 6 mol/Ls e. not enough information is given c. 9 mol/Ls f. none of the above

The enthalpy of formation of NH3 is – 46. The enthalpy change for the reaction: 2NH3 → N2 + 3H2 is ?46 KJ92 KJ–23 KJ     –92 KJ