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?
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
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?
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
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)
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, 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
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?
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
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
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 ?
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.
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
What is the relationship between 'delta' G and E (cell voltage)? 'delta' G = ?
Multiple choice question about the affect on Standard Gibbs free energy when the reactant or product pressure is increased.
In a gas phase reaction, what is the effect of increasing reactant or product pressure on the standard Gibbs free energy? a. Delta G increases due to decreased entropy b. Delta G decreases due to decreased entropy c. Delta G increases due to increased enthalpy d. Delta G may either increase or decrease e. De
If delta G is negative at all temperatures, then which of the following statements must be true? 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. None of the above
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
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
Which of the following are conditions for the standard Gibbs free energy? a. Ions or molecules in solution are present at one molar concentrations b. the temperature of the system is at 298K c. gases are present at one atmosphere partial pressure d. answers a and c are correct e. answers a, b, and c are corre
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
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
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
If "change in" G > 0, then a. K=0 b. K>0 c. K<0 d. K>1 e. K<1
The change in G and the change in H are equal: a. At O degrees Cesius b. At O degrees K c. When concentrations equal 1M and partal pressure equal 1 atm d. When all reactants and products are in the same phase e. When the reaction is exothermic
Which of the following reactions is likely to have the most positive change in entropy? a. N2(g)+3H2-->2NH3(g) b. CaO(s)+CO2--->CaCO3(s) c. N2(g)+2O2(g)-->2NO2(g) d. C(s)+)O2(g)-->CO2(g) e. 2C(s)+O2(g)-->2CO(g)
Which of the following has the least entropy? a. H20(s) b. H20(l) c. H20(g) d. Answers a and b have the same entropy e. Answers a, b, and c have the same entropy
Understanding "equation of state" (ie. PV=nRT) for an ideal gas, and using equation of state to predict changes in pressure, volume, and temperature.
In an industrial process, nitrogen has to be heated to 500 K in a vessel of constant volume. If it enters the vessel at a pressure of 100 atm and a temperature of 300 K, what pressure does it exert at the working temperature?
Working with heats of formation to calculate the amount of grams required to release a specific amount of heat.
Glucose reacts with oxygen to form carbon dioxide and water: If the heat of formation of glucose, carbon dioxide, and water are -1273.3 kJ mol-1, -393.5 kJ mol-1 and -285.8kJ mol-1. How many grams of glucose must react in order to release (1.00)(10^3)kJ of heat?
Calculate the bond energy of the reaction: 2 H2 + O2 ---> 2 H2O
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?