Calculate AS° values for the following reactions by using tabulated S° values from Appendix C in the textbook. CaCO3(s, calcite) + 2HC1(9)→CaCl2 (8) + CO2(9) + H20(1) Express your answer using four significant figures. AS° = J/K Submit Previous Answers Request Answer

Copper has been used for thousands of years, either as a pure metal or in alloys. It is frequently used today in the production of wires and cables. Copper can be obtained through smelting or recycling. Determine the energy associated with each of these processes in order to recycle 1.40 mol Cu. The smelting of copper occurs by the balanced chemical equation: CuO(s) +CO(g) → Cu(s) +CO,(g) where AHtCuo is = - 155 kJ/mol. Assume the process of recycling copper is simplified to just the melting of the solid Cu starting at 25°C. The melting point of Cu is 1084.5°C with AH®fus = 13.0 kJ/mol and a molar heat capacity, CPCU = 24.5 J/mol:°C.

A gas is compressed from an initial volume of 5.70 L to a final volume of 1.24 L by an external pressure of 1.00 atm. During the compression the gas releases 125 J of heat. What is the change in internal energy of the gas?

MISSED THIS? Read Section 7.6 (Pages 281- 284), Watch IWE 7.7 View Available Hint(s) Nitromethane (CH,NO2) burns in air to produce significant amounts of heat via the following reaction Hint 1. Calculate the number of moles of nitromethane 2CH,NO, (1) +O2(g)→ 2CO2(g) +3H,O(1) + N2(g) The value of AH is related to the balanced chemical equation by the number of moles of nitromethane. Calculate the number of moles of nitromethane in a 2.73-kg sample. AHn -1418 kJ Express your answer in moles. mol CH, NO2 44.72 Submit Previous Answers Request Answer X Incorrect; Try Again; 3 attempts remaining Convert the mass of nitromethane from kg to g. Then use the molar mass of nitromethane as a conversion factor to obtain a value in mol HA Value Units = b

10 A student heats 84.17 mL of water to 95.27°C using a hot plate. The heated water is added to a calorimeter containing 73.92 mL of cold water. The water temperature in the calorimeter rises from 2.15°C to 37.48°C. The specific heat capacity of water is 4.184 J and the density of water is g. °C 1.00 mL Assuming that heat was transferred from the hot water to the cold water and the calorimeter, determine the heat capacity of the calorimeter. J Heat capacity of calorimeter = °C

(Incorrect) Consider the following reaction: 2 PbS (s) + 3 02 (g) → 2 PbO (s) +2 SO₂ (g) AHxn=-827.4 kJ What mass of PbS has reacted if 765 kJ of heat is produced? You answered: 221. The correct answer is: 442.0g A

A 56.5 g sample of iron is put into a calorimeter (see sketch at right) that contains 300.0 g of water. The iron sample starts off at 86.7 °C and the temperature of the water starts off at 21.0 °C. When the temperature of the water stops changing it's 22.8 °C. The pressure remains constant at 1 atm. Calculate the specific heat capacity of iron according to this experiment. Be sure your answer is rounded to 2 significant digits. J 0₂-C x10 x thermometer insulated container water sample a calorimeter

4. Consider a 15.0 g piece of tin metal initially at 25 oC, What is its specific heat if adding 250 cal to it causes its temperature to increase to 125 oC.

A student is attempting to determine the heat capacity of a Styrofoam cup calorimeter by pouring hot water into a Styrofoam cup containing cold water. The student determined the mass of the cold water to be 21.2455 g and its initial temperature to be 20.36 °C. The mass of the hot water was 24.2646 g and its initial temperature as 34.54 °C. The final temperature of the water after mixing was determined to be 24.57°C. The specific heat capacity of the water is 4.184 J/(g•°C). What is the heat capacity of the Styrofoam cup calorimeter? Assume the temperature of the calorimeter is the same temperature as the cold water. 4.184 J/°C 132.5 J/°C