Which of the following is an example of an endothermic process? The combustion of methane, CH4, releasing heat. The dissolving of CaCl2, which feels warmer. The freezing of water at 0°C. The vaporization of ethanol, C2H5OH, when heated

Ice at 0.0 °C is placed in a Styrofoam cup containing 372. g of a soft drink at 15.4 °C. The specific heat of the drink is about the same as that of water. Some ice remains after the ice and soft drink reach an equilibrium temperature of 0.0 °C. Determine the mass of ice that has melted. Ignore the heat capacity of the cup. (Hint: It takes 334 J to melt 1 g of ice at 0.0 °C.) Be sure your answer has the correct number of significant digits. Note: Reference the Phase change properties of pure substances table for additional information. 1 6.D g x10 Ś

The table lists the specific heat capacities of select substances. Substance Specific heat capacity (J/g °C) lead 0.128 silver 0.235 copper 0.385 iron 0.449 aluminum 0.903 water 4.184 An unknown substance has a mass of 14.5 g.14.5 g. The temperature of the substance increases by 15.3 ∘C15.3 ∘C when 85.4 J85.4 J of heat is added to the substance.

You have 8.99 g sample of an unknown salt (MM = 116.82 g/mol). It is dissolved in 150.00 g water in a coffee cup calorimeter. Before placing the sample in the water, the temperature of the salt and water is 23.72°C. After the salt has completely dissolved, the temperature of the solution is 28.54°C. What is the Mass inside calorimeter (g)? Change in Temp inside calorimeter (C)? How much Heat gained (J)? Total Heat? How many mols of the unknown salt? What is the change in empalthy?

The heat of reaction for the reaction A + 2B → 2C is 1200. kJ.The heat of reaction for the reaction B + D → C is 150. kJ.Using Hess's Law, calculate the heat of reaction for the reaction A → 2D.

1. Magnesium solid reacts with aqueous hydrochloric acid to form the Mg2+ ion in solution. In an experiment, 60.0 mL of aqueous HCl was mixed with 0.1297 g of magnesium solid in a double Styrofoam cup calorimeter. The reaction caused the temperature of the substances in the calorimeter to rise 10.02°C. Assume the density and specific heat of the HCl solution is that of water, 1.00 g/mL and 4.184 J/g °C, respectively. The specific heat of magnesium is 1.02 J/g °C. a. Write the balanced chemical equation for this reaction. b. Calculate the heat of this reaction, AHrxn, in kJ. c. Calculate the heat of this reaction per mole of Mg2+ formed, AHxn/mole Mg²+. d. The literature value of this reaction is -466.85 kJ/mole. Calculate the percent deviation of the experimental value from the literature value.

Substance X was dissolved in a beaker of water, and it was observed that the beaker felt warmer.  This is an example of an exothermic process. true or false

110. Quinone is an important type of molecule that is involved in photosynthesis. The transport of electrons mediated by qui- none in certain enzymes allows plants to take water, carbon dioxide, and the energy of sunlight to create glucose. A 0.1964-g sample of quinone (C,H,O2) is burned in a bomb calorimeter with a heat capacity of 1.56 kJ/°C. The tempera- ture of the calorimeter increases by 3.2°C. Calculate the en- ergy of combustion of quinone per gram and per mole. 111 A I TO

An unknown sample of coal is burned in an apparatus with a calorimeter constant of 0.75 kJ/°C. When a 0.412-g sample is used, the temperature change is 9.5°C. What is the energy density of the sample in kJ/g?

A sample of aluminum, initially at 5.0 °C, was placed in 18.0 g of water, initially at 25.0 °C. The final temperature of the water and the metal was 21.0 °C. The specific heat of water is 4.184 J g-1 °c-1 and aluminum is 0.940 J g-1 °C-1. Ignore the heat capacity of the container. What is the mass (in g) of the aluminum?