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Energetics and Thermodynamics




When using a calorimeter to do detailed heat calculations, you must determine the heat capacity of the individual calorimeter you use as a calibration factor for later experiments. The fluid in a bomb calorimeter was heated for 568 seconds with a 15.00-watt heater. The temperature of the calorimeter fluid increased by 2.00 deg

Calorie and Specific Heat of Water

The calorie is an energy unit equal to about 4.2 joules. It is defined as the amount of heat required to raise one gram of water by one degree Celsius. An average person has a mass of around 68 kg. About how much energy would be required to raise an equal mass amount of water from room temperature (24 degrees celsius) to body

Balanced Equation

The decomposition of solid potassium chlorate by heating yields solid potassium chloride and oxygen gas products. Write a balanced equation for this reaction.

Reactions in Spectroscopy

1. Before spectroscopy was invented, Korner's absolute method was used to determine whether a disubstituted benzene derivative was the ortho, meta, or para isomer. Korner's method involves adding a third group (often a nitro group) and determining how many isomers are formed. A turn-of-the-century chemist isolated an aromat


General Information: The recrystallized adduct appeared as white, thin, long crystals weighing 0.3606 g and with a melting point of 123-126C. Based on the melting point ranges of the adduct sample, it was concluded that the unknown diene was alpha-phellandrene. DIRECTIONS: 1. DRAW the structure of the alpha-phellandr

Dimensional analysis

If an aluminum sphere has a mass of 23.01 grams and was heated to 137.0 Celsius and lowered into a cup containing 20.00 mL of water at 21.0 Celsius. The final temperature of the water and the sphere was 44.0 Celsius assuming no heat was loss calculate the specific heat of the aluminum in the sphere. C h2o =4.184J/g-0celsius

Reaction Prediction

Write the balanced formulas for the reactants and predicted products for the chemical reactions that follow. Also include net ionic equations. a.) A solution of formic acid, HCOOH, is oxidized by an acidified solution of potassium dichromate. b.) Concentrated hydrochloric acid solution is added to solid manganese(IV) oxide a


1.) The specific heat of a solution is 4.18 J/(grams x degrees Celsius) and its density is 1.02 g/mL. The solution is formed by combining 20.0 mL of solution A with 30.0 mL of solution B, both initially at 21.4 degrees Celsius. The final temperature is 25.3 degrees Celsius. Calculate the heat of reaction. assuming no heat i


1.) If 596 J of heat are added to 29.6 g of water at 22.9 degrees Celsius in a coffee cup calorimeter, what will be the final temperature of the water? 2.) A 5.037 g piece of iron heated to 100. degrees Celsius is placed in a coffee cup calorimeter that initially contains 27.3 g of water at 21.2 degrees Celsius. If the final te

Solid sodium metal will reacts with liquid water to form sodium hydroxide

Solid sodium metal will reacts with liquid water to form sodium hydroxide [NaOH (aq)] and Hydrogen gas. The standard Enthalpy of this reaction is -368.4 kJ. How do I write the stoichiometric/balanced equation for this reaction? How much sodium metal and water would have to be used to produce enough heat to cause th

Which OH is attacked and why

A steroid molecule is shown in the attachment. I have to explain which of the two is oxidised faster using Cr(VI) reagents. I've drawn the molecule in 3D and can say that the equatorial OH is more easily attacked than the axial one because the axial OH has axial interaction with Me causing steric hindrance to the incoming re

Gas Laws & Air Composition

1. What can cause a can to collapse? 2.The pressure at sea level in New York City is 14.3lbs./in2. Is the pressure felt by the can while it is collapsing higher or lower than this value? 3. If you placed an un-opened soda can on a hot plate and heated the can to a very high temperature. All of a sudden, the can explodes. what

Element's Atomic Weight Based on Temperature

1. If a chemical cold pack weighing 28grams and at a temperature of -2C was left in a 25C room for 3 days, what would be the final temperature of the pack? 2. I have a lab experiment where I was used Styrofoam cup with deionized water for the purpose to measure temperature of the metal which previously was boiled for 5min. I

Crystallization Problems

2. Consider a crystallization of sulfanilamide in which 10 mL of hot 95% ethyl alcohol is added to 0.10g of impure sulfanilamide. After the solid has dissolved, the solution is cooled to room temperature and then placed in an ice-water bath. No crystals formed, even after scratching with a glass rod. Explain why this crystalliza

Frequency, Wavelength, and the electromagnetic spectrum

Please show how to solve: 1) A function of wavelength (the intensity of radiation emitted by a solid) has its peak at (2.877 x 10^-3)/ (t+273.15). t represents the temp in degrees C and the peak wavelength is in m. Determine the frequency in Hz corresponding to the peak wavelength and identify the region of electromagnetic s

Boiling point of a solution given density and molecular weight

An environmentally concerned graduate student uses the more earth-friendly anti-freeze, propylene glycol (C3H8O2, density = 1.038). The final composition in her car's radiator is 30% (volume/volume) ethylene glycol (C2H6O2, density 1.114 g/ml) and 20% (V/V) propylene glycol in water. At what temperature will her engine overheat

The heat of evaporation of water is 540 cal/g

The heat of evaporation of water is 540 cal/g. the specific heat is 0.48 cal/g-c. What will final temperature be if 1020 calories are added to 10 g of water originally 100 degree C?

Hess' Law/thermochemistry

1. Use Hess's law and the thermochemical equations given below to calculate the standard enthalpy change for the reaction between C2H4 and F2. (see attached for formatted remainder) 2. (Hess's Law) Thermochemical tables tell us that the conversion of one mole of diamond to one mole of graphite is accompanied by the re

Heat Required to Convert Ethanol to its Vapor Phase

Ethanol, C2H5OH, melts at -114 degrees C and boils at 78 degreesC. The enthalpy of fusion of ethanol is 5.02kj/mol and the enthalpy of vaporization is 38.56kj/mol. The specific heats of solid and liquid ethanol are 0.97J/g-K and 2.3J/g-K respectively. How much heat is required to convert 75.0g of ethanol at -120 degreesC to t

A bowl of oil and a bowl of water

A bowl of oil and a bowl of water have been placed under a heat lamp. The temperature of each was recorded every 5 minutes in the chart below. Using the data from the chart can you determine which absorbed more heat energy? Which has the highest specific heat? If you were to plot the data on a graph using 2 lines (one fo

Multiple choice questions on energy and temperature related reactions

If ΔG is negative, a reaction is spontaneous in the forward direction. A reaction that is not spontaneous at low temperature can become spontaneous at high temperature if ΔH is ________ and ΔS is ________. a. -, - b. +, + c. +, 0 d. -, + e. +, - Which one of the following statements is true about the equilibrium

Multiple choice questions on spontaneous reactions and maximum concentration

Calculate the maximum concentration (in M) of sulfide ions in a solution containing 0.181 M of lead ions. The Ksp for lead sulfide is 3.4 x 10-28. a. 1.9 x 10-27 b. 9.4 x 10-28 c. 1.5 x 10-26 d. 3.0 x 10-25 e. 3.4 x 10-28 A reaction that is spontaneous ___________. a. will proceed as written without outside interv

4 Dissolution/Solubility Questions

1. How much N2 can dissolve in water at 25'C if the N2 partial pressure is 585. Mm Hg? 2. Hexachlorophene is used in germicidal soalp. What is its molar mass if 0.640g of the compound, dissolved in 25.0 g of chloroform, produces a solution whose boiling point is 61.93 'C? 3. The enthalpy of solution of KClo3 in water is

Reverse process activation energy

3.) Show the reaction coordinate diagram (energy diagram) for the process in which the energy change of the reaction is -60 kJ, and the activation energy is 30 kJ. What is the reverse process activation energy?

Enthalpy of Calorimeter

What is the final temperature of a calorimeter in which 5.6g of copper at 354 K is put into 56.8 g of water at 22.4 degrees centigrade?

Absolute entropy, free energy and spontaneity

1) Describe in detail the difference in absolute entropy values for the following pairs: a) C(s, graphite) and C(s, diamond) b) HCl(g) and HCl(aq) c) CH4(g) and CH3CH2CH2CH3(g) 2) a) Calculate the values of DeltaH° and DeltaS° for the following reaction at 25°C. b) Use the values from a to calculate DeltaG° for the