Auto-ionization of Water
Kw for the auto-ionization of water, H2o(l) -> H positive(aq) + OH negative (aq) is 1.0 x 10 to the negative 14. Calculate deltaGdegree,DeltaSdegree and DeltaHdegree for the reaction at 25 degree C?
Energetics and Thermodynamics
BrainMass Solutions Available for Instant Download
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
Oxygen and Spontaneous Reactions
The element oxygen was prepared by Joseph Priestley in 1774 by heating mercury oxide: HgO(s)->Hg(l) + (1/2)O2(g) delta H = 90.84 KiloJoule/mol S(Hg)=76.02 J/K x mol S(o2)=205.0 J/K x mol s(HgO) =70.29 J/k x mol Estimate the temperature at which this reaction will become spontaneous under standard state conditions.
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: Δ stands in for other symbols. PLEASE SEE ATTACHMENT FOR PROPER FORMULA SYMBOLS. Given the following data: ΔGf Ca2+(aq) = -553 kJ / mol ΔGf Cl-(aq) = -131 kJ / mol ΔGf CaCl2(s) = - 748 kJ / mol ΔGhyd Ca2+(g) = -1517 kJ / mol ΔGhyd Cl-(g) = -334 kJ / mol a) Write
Calorimetry and work
One mole of water evaporates in an open container at 273 Kelvin. The formula is H20 liquid---->>>>H20 gas. What is the work done on or by the system? a. 2.3 kJ b. -2.3 kJ c. 22kJ d - 22kJ
Inorganic Thermodynamics Ionic Materials Related
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)
Standard Free Energy Change, Atomic Mass, pH, Molality
8 general chemistry questions involving: standard voltage/free energy exchange, atomic number/mass, pH, balancing equations, molality/molarity and more. Example: When the eqation for the half reaction above is balanced, what is the ratio of the coefficients OH- : Cr02- (a) 1 : 1 (b) 2 : 1 (c) 3 : 1 (d) 4 : 1 (e) 5 : 1
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
Thermodynamic Quantities of Peroxydisulfate Ion (S2O8-2)
I want the thermodynamic quantities of S2O8(-2). In other words, I want the standard free energy of formation, standard heat of formation, and the standard entropy of the S2O8(-2) ion under aqueous conditions.
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
Evaluting Melting Point Determination
1. In a mixture of approximately 20% camphor and 80% naphthalene. What would you expect the melting point to be? (+/-)camphor (175-177 Celsius) and naphthalene (80-81 Celsius). 2. Describe the expected type of error in the observed m.p. (unaffected, high, low and/or broad) when the melting point is determined as follows: a.
Entropy of mixing
I am trying to figure out how, for the entropy of mixing of two polymers, one gets from: Change in entropy of mixing (delta S sub m) = k[(N1 + N2) ln (N1 + N2) - N1 ln N1 - N2 ln N2] to the result: change in entropy of mixing (delta S sub m) = -k(N1 ln v1 + N2 ln v2) where v1 and v2 are the volume fractions of the two
What is the percent of CdSO4 by mass in a 1.0 molal aqueous solution?
1. What is the percent of CdSO4 by mass in a 1.0 molal aqueous solution? 2. Calculate the amount of heat that must be absorbed by 10.0 gram of ice at -20 C to convert it to gaseous water at 110 C. Given: Specific heat ice = 2.1 Joule/gram water = 4.184 Joule/gram steam = 1.84 Joule/
Molar enthalpy of vaporization
The normal boiling point of bromine is 58.8 C. Given that the vapor pressure pressure of methanol (sic) is 75.0 torr at 2.5 C, Calculate the molar enthalpy of vaporization of bromine. Show all work and thanks for your help and time.
Vapor Pressure Sample Question
The vapor pressure of ethanol is 400 mmHg at 63.5 C. Its molar enthalpy of vaporization is 39.3 K Joule/mol. What is the vapor pressure of ethanol, in mmHg, at 34.9 C? Show work. For iodine, the molar enthalpy of sublimation is 62.3 k Joule/mol. The molar enthalpy of fusion is 15.3 k/Joule/mol. Calculate the molar enthal
Melting and Vaporizing Substances
Show the heating curve of a subtance that melts and then vaporizes. (a) Sketch the heating curve of carbon dioxide at atmospheric pressure, starting at -100 C and ending at 30 C. (b) Sketch the same heating curve as it would appear at a pressure of 10 atm. (c) Under what conditions would the heating curve resemble the on
Colligative Properties - Boiling Point and Freezing Point of Water
Show how the boiling point and freezing point of water are affected by the addition of various solutes. (a) If you were to dissolve 10 g sodium chloride in 500 g water, what would be the boiling point of the solution? (b) If you were to heat the solution in part (a), and continue heating it as it boiled, what would happen to th
Enthalpy Of Solution
Look at the dissolution of various salts. Compare the dissolution of sodium hydroxide with that of sodium chloride. a) How do the energy changes for the overall processes compare? b) Discuss the difference in magnitude of each of the three steps for dissolution of the two compounds.
Working with a rapid method to convert iron to rust
I'm working on an experiment that requires the rapid (minutes rather than days) conversion of Iron into red rust (Fe2O3) WITHOUT using heat as a catalyst. The reverse reaction (also without heat as a catalyst) would also be helpful.
Heat of formation
Methylene chloride can be prepared from the reaction of methane and chlorine, by the following equation: CH4(g) + Cl2(g) ---> CH2Cl2(g) + HCl(g) Calculate the standard heat of formation in kilojoules for the reaction using the following measured heats of formation. HCl(g) + CH3Cl(g) --> CH4(g) + Cl2(g) Delta H = +98.3 kJ CH
Entropy Change
Question: The reaction of ammonium nitrate when added to water is endothermic (H=25.7 kJ) and can be written as: NH4NO3(s) + H2(l) ---> NH4NO3(aq) a) Determine the heat of formation of NH4HO3(aq). b) What would be the final temperature of a solution that contained 50 grams of NH4NO3 dissolved in 125 mL of water. Use a spec
Mass of carbon sample
The mass, in g. of carbon in a sample that requires 530 J to heat from 23.6 degree C. to 54.2 degree C. (s carbon=0.71 J/(g.degree C.)