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Energetics and Thermodynamics


A] What type of calorimetry is used to determine the heat evolved by burning a gummy bear (promarily glucose) B] If the gummy bear weighs 1.25g and the temp of the calorimeter increases by 50 degrees C how much heat is absorbed / released by the reaction?

Final Temperature (Compare Substances)

You place 2 beakers at 25 degree C on a hot plate Beaker A = 100.0mL Beaker B = 100.0mL Each absorbs 15.0 Kj of heat. A) What is the final temp of each liquid? B) Why would one liquid be hotter than the other?

Calorimetry - Final Temperature

I just need to know the formula for this problem I cannot find it in my book. If you have 2.40 mol of Au at 100 degrees C and is added to 10.mol of water at 25 degrees what will be the final temp...cpAu=25 J/Km and cp of water=75.3J/Km. Thanks

Activation energy

I am trying to find deltaH. The activation energy is 128kJ for this reaction. The activation energy for the reverse reaction is 95kJ. In the presence of a catalyst Eacat is 110kJ.

Heat and Heats of Formation

The question states: Given 2BaCO3(s) ---> 2Ba(s) + 2C(s) + 3O2(g) Change in H = 2432.6kJ First they ask for me to determine the heat of formation of BaCO3. My problem is how do you determine the heat formation of the reactant (in this case) when you are given a change in H for the whole thing. Secon

Saturated and Supersaturated Solutions

Take a saturated solution, for example, let's use salt water. At room temperature, you totally saturate the solution. Then, you slowly heat the solution, and suddenly you can add more. Does this make it a super saturated solution? Also, once you take the solution back down to room temperature, will salt crystals reappear i

Calculating Calories of Heat Produced

a) If 5.0 moles of H2 react, how many calories of heat are produced? (Using the bal equation: N2 + 3H2 -> 2NH3 + 21941 calories) b) How many grams of H2 are needed to produce 55.0 grams of NH3? c) Is this reaction endothermic or exothermic?

Understanding Gibbs Free Energy Change

What is Gibbs free energy? What is the difference between entropy and enthalpy? What does the useful work derived do such that the entropy increases (additional to that increased along with enthalpy) but enthalpy remains the same (i.e the useful work does not increase the enthalpy)?

Enthalpy of Vaporization

Water has an enthalpy of vaporization of 40.7 kJ/mole. What is the boiling point of water at 260. Torr? Do we use the vapor pressure formula here? How do we answer? Thank you.

Vapor pressure and boiling point solution

This is a question about finding boiling point of water with the vapor pressure formula. The question states In Breckenridge, Colorado, the typical atmospheric pressure is 520 torr. what is the boiling point of water (delta Hvap = 40.7 kJ/mol) in Breckenridge? Using the vapor pressure formula Do we pick the ln(P1/P2)=

Vaporization and Pressure

Please explain how you get the answer for the following question: How many kilojoules of heat are required to raise the temperature of 0.750 L of ethanol (d=0.789 g/mL) from 0.0 to 25 degrees Celsius and then to vaporize 10% of the sample? The specific heat of ethanol is 2.46 J g (to the -1 power) and degrees Celsius ( to th

Enthalpies of Vaporization

To vaporize a 1.50 g sample of liquid benzene C6H6 requires 652 J of heat. What is change of heat vapn of benzene in kilojoules per mole?

Solution and Solvent Problems

1. Calculate the molality of a solution of 14.0 g of Mn(NO3)2 in 250 g of water. 2. Calculate the molarity of a solution made by taking 60.0 mL of 2.79 M. NaOH and diluting it to a final volume of 260mL. 3. A natural alcohol has been isolated by an ethnobotanist working in the Amazon. A solution of 6.38 g of this alcoho

Extent of reaction as function of temperature

If given the change in entropy and the change in enthalpy, derive an expression for the extent of the reaction as a function of temperature. Please look at the attached diagram for an adequate description.

Determining the Efficiency of a Water Heater

Some of the butane, C4H10(g), in a 200.0 liter cylinder at 25.0 degrees C is withdrawn and burned at a constant pressure in an excess of air. As a result the pressure of the gas in the cylinder falls from 2.35 atm to 1.10 atm. The liberated heat is used to raise the temperature of 132.5 liters of water from 25.0 to 62.2 degree

Carbon Monoxide and Hydrogen Reaction

Consider the reaction CO(g) + 2 H2(g) <-> CH3)H(l) at 25 degree C. Change Gdegree(CO) =-137.3 KJ/mol change Gdegree (CH3OH)= 166.3 KJ/mol change in Hdegree (CO) = -110.5 KJ/mol change in Hdegree (CH3OH) = 238.7 KJ/mol Sdegree (CO) = 197.9 J/K x mol Sdegree (CH3OH)= 126.8 J/K x mol Calculate Sdegree(H2(g)) Show

Decomposition of Nitrosyl Chloride

Nitrosyl chloride (NOCl) decomposes at elevated temperatures according to the eqation 2 NOCl(g) <-> 2 NO(g) + Cl2(g) Calculate Kp for this reaction at 227 degrees C. For this reaction change in Hdegree =81.2 KJ/mol, change in Sdegree= 128 J/K x mol

Calculating Heat of Combustion

The DH of combustion of CH4 is -882kJ/mol.How many grams of water, which has a specific heat of 4.184 J/g-oC can be heated from 30oC to 95oC by the heat produced in the combustion of 2.25 mol of CH4?

Spontaneous Reactions and Entropy

Consider the reaction : 2H2(g) + O2(g) ---> 2H2O(l). In this reaction, matter is less dispersed, leading to a decrease in entropy since the reactants are gases and the product is liquid. Nevertheless, the reaction is spontaneous. Explain why this is so.

Inorganic Thermodynamics: Corresponding Reactions

Note: &#61508; stands in for other symbols. PLEASE SEE ATTACHMENT FOR PROPER FORMULA SYMBOLS. Given the following data: &#61508;G&#61616;f Ca2+(aq) = -553 kJ / mol &#61508;G&#61616;f Cl-(aq) = -131 kJ / mol &#61508;G&#61616;f CaCl2(s) = - 748 kJ / mol &#61508;G&#61616;hyd Ca2+(g) = -1517 kJ / mol &#61508;G&#61616;hy

Inorganic Thermodynamics

Aluminum oxide (Al2O3) is a widely used industrial abrasive (corundum, emery), with its specific application depending on the hardness of the crystal a) How is the hardness of an ionic material related to its lattice energy? b) Knowing the relationships between lattice energy and: 1) charges and 2) atomic radii, would you

Inorganic Thermodynamics: Enthalpy Change

Question: For water, (delta) Hfus = + 6.01 kJ/mol and (delta) Hvap = +40.67 kJ/mol. What is the enthalpy change associated with the deposition of 1.24 mol of water vapor?

Inorganic Thermodynamics

Calculate the standard enthalpy of formation of gaseous diborane, B2H6, using the following thermochemical information: (See attachment for full question)

Inorganic Chemistry Midterm Study Guide

Please do all of the midterm. These are the sections that will be covered in our midterm please complete with long explanations as well as giving related info to questions asked. Thanks.

Heat Loss and Specific Heat

a) A student wishes to determine the specific heat of a metal using a coffee cup calorimeter (calorimeter constant 50.35 cal/degrees Celsius). The student heats 130.56 grams of unknown metal from 25.0 degrees Celsius to 100.4 degrees Celsius. The initial temperature of the calorimeter (coffee cup plus 30 mL water) was 23.5 degre

Work of expansion

One mole of nitrogen gas confined within a cylinder by a piston is heated from 9.1°C to 883.6°C at 1.30 atm. Calculate the work of expansion (include sign) in joules (1 J = 9.87à?10-3 atm L). Assume all of the energy is used to do work.

Reaction equations and mass

Please give step by step solutions and answers. 1) Write the balanced molecular equation for the reaction of calcium with molecular oxygen to form calcium oxide. 2) You start out with an empty crucible weighing 19.3350g. After adding some calcium to the crucible, the mass is now 22.1156g. After heating the calcium and co

Combustion & Mass

Limestone(CaCO3) is used to remove acidic pollutants from smokestack flue gases in a sequence of decomposition-combination reactions. The limestone is heated to form lime (CaO), which reacts with sulfur dioxide to form calcium sulfite. Assuming a 74.7% yield in the overall reaction, what mass of limestone is required to remove a

Chemistry review questions

Question 2 An imaginary element X consists of two isotopes having masses of 110.00 amu and 112.00 amu. ("amu" is an atomic mass unit.) A sample of X was found to consist of 79.94% 110X and the rest is 112X. What would be the average atomic mass of X in this sample? Give your answer to four significant figures. Do not enter a