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Energetics and Thermodynamics

Chemistry Problem Set: Heat Energy and Temperature

The specific heat capacity of benzene is 1.74J/g*K. What is its molar heat capacity (Jmol*K)? What quanity of heat is required to raise the temperature of 50.00mL of water from 25.52 to 28.75C? The density of water at this temperature is 0.997 g/mL. When 108g of water at a temperature of 22.5C is mixed with 65.1g of wat

General chemistry questions

23) ....CrOsub2^- + ... OH^-...CrOsub4^2- + ...Hsub2O+ e^- When the equation for the half reaction above is balanced what is the ratio of the coefficient's OH^-: CrOsub2^-? a) 1:1 b) 2:1 c) 3:1 d) 4:1 e) 5:1 24) CuO(s) + Hsub2(g) <--- / ---> Cu(s) + Hsub2O(g) triangle H = -2.0kJ The Substances in

Gas Law Problem

Nitrogen and Hydrogen gases react to form Ammonia. A closed, rigid cylinder contains a total of 0.750 mol of gas at 25 degrees C and 1.10 atm before the reaction takes place; the mole ratio of hydrogen to nitrogen in the cylinder is 3:2. Determine the temperature and pressure of the gas in the cylinder at the end of the reaction

Simple Entropy

Please help with the following problems. A) Define entropy. Why is entropy considered an absolute quantity? B) For each of the pairs of substances below, choose the one expected to have the greater absolute entropy. Explain your answer. Assume 1 mol of each substance. i) Cu(s) or C(graphite) at the same temperatu

Thermodynamic Data and Standard Enthalpy of Decomposition

Use thermodynamic data to calculate the standard enthalpy of decomposition of liquid hydrogen peroxide into water and oxygen gas: H2O2(l)-->H2O(g) + 1/2 O2(g). Calculate the energy released by the decomposition of 1.0 g of 90% hydrogen peroxide solution. Molar mass of hydrogen peroxide = 34.0 g/mol. Estimate the final temperat

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


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 -

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

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

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

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


If "change in" G > 0, then a. K=0 b. K>0 c. K<0 d. K>1 e. K<1

Working with enthalpy of formation.

The reaction of 4.49 g of carbon and 9.21 g of oxygen, produced carbon dioxide, and 113.2 kJ of heat. What is the enthalpy of formation of carbon dioxide?

Absolute entropy

Delta G sub f for Al203 = -1582 kJ/mol delta H sub f for Al203 = -1676 kJ/mol 1. Calculate absolue entropy for S for oxygen (g) if: S for Al(s) = 164 J/mol K S for Al2O3 (s) = 51.0 J/mol K 2. Calculate the heat required to raise the temperature of 35.0 g of aluminum from 800 degrees C to 2600 degrees C 3. To c

Galvanic Cell, Laws of Thermodynamics, Equilibrium, Etc.

Chemistry review problems, please see the attachment. PART QUESTION 1: A) i) Sketch the galvanic cell based on the following two half-reactions. Indicate (i) the balanced cell reaction, (ii) Eo for the cell, (iii) which electrode is the anode and which the cathode, (iv) the direction of electron flow. Au3+ (aq) + 3e- 

Thermal Chemistry

I'm having problems understanding the ideas in the topic of thermal chemistry and would appreciate any sort of overview of the main concepts you could provide.