Energetics and Thermodynamics

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Calculating the Entropy of Argon

The experimental specific heat capacity of argon is 0.5213 J/g/K at a pressure of 1 atmosphere at 300 K. Argon's entropy at 300 K is 3.877 J/g/K. Use these data to calculate the entropy of argon at 500 K.

Estimating temperature inside a cylinder of an internal combustion engine

Estimate the temperature inside a cylinder of an internal combustion engine just after the spark has ignited the fuel. You are provided with the following list of assumptions. Assume the cylinder has a volume of 10 liters. Assume that the oxidant is air containing 20% oxygen. Assume that the fuel is octane (C9H18, molar mass = 1

Chemistry-Thermodynamics

When an explosive is detonated inside a shell or cartridge case, the explosion effectively takes places in a closed or fixed volume container. (The chemical decomposition is fast compared to the rate at which the projectile can gain velocity.) You can make an estimate of the explosion temperature if you assume a constant volume,

Enthalpy of Formation of CaO

Calcium metal burns according to the following equation: Ca(s) + 1/2 O2(g) --> CaO (s). When 1.00 g of calcium metal is burned in a constant pressure calorimeter with a heat capacity of 15.20 kJ/K, the temperature increases by 1.04 degrees Celcius. Calculate the enthalpy of formation of calcium oxide. Compare this answer with -

Chemistry - Calorimetry

Coal used to fire a power plant has an energy value of 13,250 Btu/lb. A 0.2500 g sample of this coal is combusted in a bomb calorimeter with a heat capacity of 4,589 J/K. Calculate the temperature rise of the calorimeter?

Adiabatic Monotonic Ideal Gas Expansion

A 0.5 mol of an adiabatic monotonic ideal gas in a container at 250kPa and 350K is allowed to expand in either of the follow: a) reversibly or b) against a constant pressure of 150kPa until a final pressure of 150kPa is reached. Please find the final temperature, delta U, delta H, q, and w for each process (a and b).

A simple problem set of 10 simple, short first year problems.

4. The term proof is defined as twice the percent of volume of pure ethanol in solution. Thus a solution that is 95% ethanol by volume is 190 proof. What is the molarity of ethanol in a 92 proof ethanol water solution? (density of ethanol is .8g/cm3; mol. wt. of ethanol is 46). 6. Find the mass percent of CuSO4 in a solut

maximum temperature of water when aluminum is dropped in

A piece of aluminum with a mass of 234 grams is heated to a temperature of 231 degrees Celcius and then is dropped into 123 mL of 21 degrees celcius water. If no energy is lost to the surroundings, what will be the maximum temperature reached by the water?

2 Chemistry questions

1) The Zinc in a 1.200g sample of foot powder was precipitated as ZnNH4PO4. The strong heating of the precipitate yielded 0.4089g of Zn2P2O7. Calculate the mass percent of zinc in the sample of foot powder. 2. A mixture contains only sodium chloride and potassium chloride. A 0.1586g sample mixture was dissolved in water. It t

Physical Chemistry: Heats of Formation Calculation

Tables are available for heats of formation of common compounds and ions in aqueous solution in most general chemistry textbooks. Calculate DH for the following reaction: 8 Al(s) + 3 Fe3O4(s) --> 4 Al2O3(s) + 9 Fe(s)

Calculation of bond energies and enthalpies.

You may wish to review the Laws of Thermochemistry and Endothermic and Exothermic Reactions before you begin. A table of single bond energies should be used as a help (available in most general chemistry text books). Estimate the change in enthalpy, DH, for the following reaction: H2(g) + Cl2(g) --> 2 HCl(g)

Ligand binding

Could you take a look at some problems that I have answered to see if I'm in the right direction. (a) Using this plot, estimate the enthalpy and entropy of binding for each protein to DNA. (b) What is the free energy change for the binding of WT1 and EGR1 to DNA at 25oC? (a) For each of the proteins: is the binding to

Isooctane problem: balanced combustion equation, standard volume, heat of combustion

Isooctane, C8H18, is the component of gasoline from which the term octane derives. A) Write a balanced equation for the combustion of one mole of isooctane to yield CO2(g) and H2O(l). B) What is the volume (in liters) of CO2 at STP? C )The standard molar heat of combustion (delta Hrxn for the reaction is -5,456.6 kJ/mol. Calc

Explaining Why a Reaction Is Not Spontaneous

Consider the reaction : 2(H2O)l = 2(H2)(g) + O2 (g) This reaction has a dispersal of matter since a liquid produces two gases, yet the reaction is not spontaneous. Why is this?

What equation is needed to find temperature?

Given the moment of inertia of 12C16O is 1.457e-46kgm^2, at what temperature would the population of particles in the J=4 state be 1/8 the population of molecules in the J=0 state?

Reaction Mechanism

A reaction occurs with the following stoichiometry A + P -> AP The concentration of A was measured versus time after mixing, the data are the following: [A](nM) Time (s) 50 0 40 100 30 229 20 411 10

Reaction Mechanisms

The reaction of a hyrogrn halide A with an olefin B to give product P according to the stoichiometric relationship: A + B -> P is proposed to occur by the following mechanism: 2A <-> A2 (fast to equilibrium) A + B <-> C (fast to equilibrium) A2 + C -> P + 2A (slow) (a) Based on this mechan

energy content of Glucose

The enthalpy change involved in the oxidation of Glucose is -2880 kJ/mol. 25 % of the energy is available for muscular work. If 100 kJ of muscular work is needed to walk one kilometer, what is the maximum distance that a person will be able to walk after eating 120 g of glucose ?

Prevent energy storage in body by drinking water ?

An athlete is given 100 g of Glucose (C_6 H_12 O_6) of energy equivalent to 1560 kJ. He utilises 50 % of this gained energy in the event. In order to avoid storage of energy in the body, calculate the mass of water he would need to perspire. The enthalpy of evaporation of water is 44 kJ/mole.

Chemistry Sample Solution: Entropy For Reaction

Calculate "delta" S for the following reaction: H2(g) + Br2(l) --> 2HBr(g) given: S[H2(g)] = 0.131 kJ/K S[Br2(l)] = 0.152 kJ/K S[HBr(g)] = 0.199kJ/K a. 0.482 kJ/K b. 0.681 kJ/K c. 0.115 kJ/K d. -0.084 kJ/K e. 0.084 kJ/K

Relationship between delta G and E

What is the relationship between 'delta' G and E (cell voltage)? 'delta' G = ?

The relationship between delta S and G

Predict the signs of delta S and delta H for the melting of ice at 300K? a. Delta H > 0 and delta S > 0 b. Delta H > 0 and delta S < 0 c. Delta H < 0 and delta S > 0 d. Delta H < 0 and delta S < 0 e. Not enough information provided to answer question

Calculating delta S

Calculate "delta" S for the following reaction: H2(g) + Br2(l) --> 2HBr(g) Given: S[H2(g)] = 0.131 kJ/K S[Br2(l)] = 0.152 kJ/K S[HBr(g)] = 0.199kJ/K a. 0.482 kJ/K b. 0.681 kJ/K c. 0.115 kJ/K d. -0.084 kJ/K e. 0.084 kJ/K

Multiple choice question about the effect on Gibbs free energy from increasing the reactant or product pressure.

In a gas phase reaction, what is the effect of increasing reactant or product pressure on the standard Gibbs free energy? a. it increases due to decreased entropy b. it decreases due to decreased entropy c. it increases due to increased enthalpy d. it may either increase or decrease e. it is unchanged

Entropy and Combustion of Hydrogen Gas

Which of the following is true for the combustion of hydrogen gas? a. "change in" H > 0 b. "change in" H < 0 c. "change in" S > 0 d. "change in" G > 0 at 300K e. "change in" G > 0 at all temperatures

Entropy, enthalpy and the freezing of water

Which of the following is true for the freezing of water at 298K? a. "change in" H < 0 b. "change in" H > 0 c. "change in" S = 0 d. "change in" S > 0 e. both answers a and d are correct

Entropy, Matter and Temperatures

Which of these statements is false? a. For a given material, a gas would have a greater entropy than the solid. b. For a given material, a liquid would have a greater entropy than the gas. c. At 0 K, an ordered pure crystalline solid has an entropy of zero. d. For a given material, the liquid has a greater entropy than the

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