Given the standard enthalpy changes for the following two reactions: Use the References to access important values if needed for this question. (1) 2Ni(s) + O₂(g) → 2NiO (8) (2) 2Hg(1) + O₂(g) → 2HgO(s) Standard enthalpy change = What is the standard enthalpy change for the following reaction? (3) NiO(s) + Hg(1)→ Ni(s) + HgO(s) AH =? kJ Submit Answer AH-479.4 kJ ΔΗ° = – 181.6 kJ Retry Entire Group 9 more group attempts remaining

When methanol, CH, OH, is burned in the presence of oxygen gas, O₂, a large amount of heat energy is released. For this reason, it is often used as a fuel in high performance racing cars. The combustion of methanol has the balanced, thermochemical equation CH₂OH(g) + O₂(g) → CO₂(g) + 2 H₂O(1) AH = -764 kJ How much methanol, in grams, must be burned to produce 983 kJ of heat? mass: g

Important values if needed for this question. A scientist measures the standard enthalpy change for the following reaction to be -901.8 kJ : Fe203(s) + 2 AI(s): Al203(s) + 2 Fe(s) Based on this value and the standard enthalpies of formation for the other substances, the standard enthalpy of formation of Al203(s) is kJ/mol.

2. A small immersion heater was used to heat water in an insulated cup. The heater was placed in 100.0 g of distilled water initially at 21.0°C, and turned on for 60.0 seconds while the water was stirred with a thermometer. The final temperature of the water was measured to be 37.5°C. Assume the specific heat capacity of the water is 4.18 J/g °C. (a) Calculate the total heat energy in joules absorbed by the water and the average power in watts (1 watt = 1 joule/s) delivered by the heater. The heater was used to deliver 3000 joules of energy to 100.0 g of methanol (CH,OH(E)) in the same manner. The temperature of the methanol increased by 11.8 Celsius degrees. (b) Calculate the specific heat capacity of the methanol liquid. (c) (i) Calculate the mass of water (H,O, Co= 4.181 Jgl °C-) at 20.0°C that would be requireć %3D to cool a 30.0-g block of copper (Cu, co0.385 J gl °C-l) from 50.0°C to 25.0°C in an insulated cup. %3D (ii) Which liquid, water or methanol, would be more effective as…