1. Water ice melts to form liquid water. The thermochemical equation for this process is H2O(s)H2O(0)Hmelt=6.02kJ i) Is this reaction endothermic? ii) A standard hockey rink contains 2000kg of ice. How much heat is absorbed when an entire rink melts? iii) How many grams of ice melt when 2.44kJ of heat is absorbed from the surroundings? iv) How much energy is released when 2000kg of water is refrozen to repair the hockey rink? v) What's the difference between the energy required to melt the ice and the energy to refreeze it? 2. Steam is produced when water is heated according to this thermochemical equation: H2O(i)H2O(g)Hvap=40.2kJ i) Mr. Knight is making Kraft Dinner for lunch (like a boss). How much heat does he need to produce to boil 1L of water so that he can cook his lunch? ii) The steam from the boiling pot of water condenses on the ceiling above Mr. Knight's Mac and Cheese. A total of 35mL of water condenses to the ceiling. How much energy is released to the environment when this happens? 3. Nitric Oxide (NO) is produced when nitrogen combusts in the atmosphere according to the following equation: N2(g)+O2(g)2NO(g)Hma=180.6kJ Calculate the enthalpy change of the surroundings when 2.5g of N2 reacts with a sufficient amount of oxygen. 4. Mr. Knight drives a relatively fuel efficient car. While driving to school today, he burned a total of 6000g of octane (C8H18) according to the following equation: 2C8H180)+25O2(0)16CO2(2)+18H2O(0)Hrun=5470.2kJ i) How much heat (enthalpy) did Mr. Knight transfer from his car to the atmosphere? ii) Yesterday, Mr. Knight calculated that he produced 300g of H2O while driving to the grocery store. How much heat did he transfer? iii) How could Mr. Knight produce less heat to the atmosphere? Should he care about the heat his car is producing? 5. Justin Bieber got hit in the face with a water bottle and broke his nose. To reduce the swelling he placed a cold pack on his nose. The cold pack cools according to the following reaction: (H sol = enthalpy change from dissolving in water) NH4NO3(s)+H2O(l)NH4+(aq)+NO3(aq)Hsol=26.7kJ i) The heatpack absorbs 2.2kJ of heat from poor Justin Bieber's face. How many grams of NH4NO3 were in the ice pack? ii) Justin Bieber's face is still swelling, so he grabs a new, larger ice pack. How much heat would be absorbed from his mangled face if his new ice pack contains 454g of NH4NO3 ? 6. Vinegar (CH3COOH) reacts with baking soda to form sodium citrate and water according to the following reaction: CH3COOH(aq)+NaHCO3(s)CH3COONa(aq)+H2O(l)+CO2(g)Hrnn=11.2kJ i) How much heat is lost from the surroundings if 400g of vinegar is combined with a sufficient amount of NaHCO3 ? ii) Mr. Knight fills a balloon from this reaction with 20g of CO2. How much vinegar was used? What was the change in enthalpy to the surroundings