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Energetics and Thermodynamics

Enthalpy change

10. Look at the enthalpy cycle below... a) What enthalpy change is represented by delta H1? b) What are the combined enthalpy changes represented by delta H2? c. What enthalpy change is represented by delta H3? d. write and equation that links delta H1, delta H2, and delta H3. e. use the answers from parts a and d and the f

Description of Heat Capacity

Calculate the specific heat capacity of benzene(C6H6), given that 192 J of heat is required to raise the temperature of a 20.0g sample of benzene from 25.2 C to 38.8 C. What is the molar heat capacity of benzene? (the molar heat capacity is the heat capacity of 1 mole of benzene) 3.50 Kcal of heat is removed from a 1.50 Kg

Endothermic Reaction

THE ENDOTHERMIC REACTION A(g) + B(g) 2C(g) PROCEEDS TO AN EQUILIBRIUM CONDITION AT 200 CELSIUS. WHICH OF THE FOLLOWING STATEMENTS IS (ARE) TRUE? 1- If the mixture is transferred to a reaction vessel of twice the volume, the amounts of reactants and products will remain unchanged 2- Addition of an app

Activation Energy

For the reaction CO+NO2>CO2+NO the activation energy for the forward reaction is 135 kJ/mol of CO activated. a) Determine the heat of reaction. b) From the data given, and the ^Hr for the reaction, determine the activation energy for the reverse reaction.

Moles Produced from Heating

1. How many moles of carbon dioxide will be produced if 50g of potassium hygrogen carbonate are heated? 2. Also, What is the mass of one nitrogen molecule (in grams). Do they mean N_2_? Thanks! : )

Calculating delta G

I am trying to understand how to balance this equation. We were given the following data to solve for delta G (standard). S(s) + 3/2 O2(g)--------->SO3(g) delta G standard = -371kJ 2SO2(g)+ O2(g)--------->2SO3(g) delta G standard = -142kJ Now calculate delta G standard for the reaction. delta G standard = d

Delta Heat for a Reaction

Evaluate Delta H (standard) for the reaction below at 25 degress celcius SiO2 (s) + 4HF (aq) >>>>>>> SiF4 (g) + 2H2O (l) Delta H standard f (kj/mol) -910.9 -320.8 -1615 -285.8

Solve this Standard Heat of Reaction Problem

Given the standard heats of formation for the following compounds, calculate the change H2 degrees 98 for the following reaction: CH4 (g) + H2O (g) >>>>>> CH3OH (l) + H2 (g) Change in H Degree F (kj/mole) -75 -242 -238 0 I need to see how to solve this, and most importantly, the answer.

Lattice Energy of MgO

Write the reaction involved with lattice energy for MgO. Class example said steps to find delta E is 1) Write formation for reaction, 2) Form gases to elements, 3) dissociate diatomics, 4) remove electrons from cation, 5) add electrons to anion, 6) form solid.

Solubility and Gibbs Free Energy Questions

1. Firstly, how do you calculate the molar solubility of AgBr when given 0.1 M AgBr at 25 degrees C (Ksp = 5 x 10^-3)? If show me a few examples of how to calculate molar solubility when you're given different things, I would appreciate it. 2. Next, how can I calculate the squilibrium direction of CO2 at 25 degrees C and 9

Heat Related Problems

Hi, I need some assistance with the following questions: 1) You have two pieces of Al metal - one is a thin piece of Al foil, and the other is a thick block. Both have the same length and width. Which will absorb more heat when set on a hotplate for the same period of time to raise the temperature 5 degrees? a) Block b) Fo

Calorimetry

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?