Concept explainers
Phosphorus exists as several allotropes that have varying properties. The enthalpy of transition from white P to red P,
Interpretation:
The temperature at which the white phosphorus becomes the stable phase at
Concept introduction:
The clausius-clapeyron equation states the relation between vapor pressure and the absolute temperature.
The alternate form of Clausius-Clapeyron equation is,
Answer to Problem 6.25E
The temperature at which the white phosphorus become the stable phase at
Explanation of Solution
Given
The density of white phosphorus is
The density of red phosphorus is
Molar mass of phosphorus is
The enthalpy of transition from white P to red P,
The alternate form of Clausius-Clapeyron equation is,
The final temperature is calculated by the equation,
First, the molar volumes of each phosphorus atom are calculated with the help of their densities. The molar volumes are calculated by the formula,
Substitute the values of molar mass and density of white phosphorus,
Similarly, the molar volume of red phosphorus is calculated as,
The initial temperature,
The conversion of Celsius to Kelvin is done as,
Therefore, the conversion of
The initial pressure,
The final pressure is
Substitute the values of the enthalpy of transition, change in molar volume, pressure and initial temperature in equation (2) to calculate the final temperature.
Simplify the above expression,
Hence, the temperature at which the white phosphorus become the stable phase at
The temperature at which the white phosphorus become the stable phase at
Want to see more full solutions like this?
Chapter 6 Solutions
Bundle: Physical Chemistry, 2nd + Student Solutions Manual
- Boron nitride (BN) has a structure similar to graphite, but is a white insulator rather than a black conductor. It is synthesized by heating diboron trioxide with ammonia at about 1000°C. (a) Write a balanced equation for the formation of BN; water forms also.(b) Calculate ΔH°rxn for the production of BN (ΔH°f of BN is -254 kJ/mol).(c) Boron is obtained from the mineral borax, Na₂B₄O₇.10H₂O.How much borax is needed to produce 1.0 kg of BN, assuming 72% yield?arrow_forwardThe Haber process is very important for agriculture because it converts N2(g) from the atmosphere into bound nitrogen, which can be taken up and used by plants. The Haber process reaction is N2(g) + 3 H2(g) = 2 NH3(g). The reaction is exo- thermic but is carried out at relatively high temperatures. Why?arrow_forwardThe ionic radii of the Mg21 and 022 ions are 0.86 Å and 1.26 Å, respectively. Given that the compound magnesium oxide, MgO, forms a cubic-type lattice of some type, calculate a value for its density. As part of your answer, speculate on the lattice formed by the oxide ions and the type of holes occupied by the magnesium cations.arrow_forward
- Write the balanced chemical equation for conversion of Al(s) to KAl(SO4)2·12H2O(s) in aqueous solution.arrow_forwardA metal crystallizes in the face-centered cubic crystal structure with a unit cell edge of 3.52 x 10 -8 cm.The density of the metal is 8.90 g/cc. (a) What is the mass, in grams, of a single atom of this element? (b) What is the atomic weight of the element (g/mol). (c) What is the radius, in cm, of an atom of the element?arrow_forwardThe density of platinum is 21.45 g/cm3. It crystallizes in a fcc lattice. Calculate its metallic radius.arrow_forward
- Niobium crystallizes in BCC structure and has a density of 8.55 g/cm^3. Calculate its atomic radius if its atomic mass is 93 g/mol. *arrow_forwardif you can. If there is not enough information to decide, choose can't decide in the element 1 2 3 description Element 1 is a hard dark-red solid. A 10. g cube of it is set on a hot plate. After 10 minutes, the temperature of the top of the cube has risen by less than 1 °C. Element 2 is a moderately soft silvery-gray solid. A 5 cm x 5 cm square of it, only 1 mm thick, is flexed slightly by hand. The sheet snaps in half. Element 3 is a moderately soft silvery-gray solid. A small cube of it is put into a ceramic crucible and heated strongly. It melts about not far above room temperature. metal or nonmetal? O metal O nonmetal O (can't decide) O metalk O nonmetal O (can't decide) O metal O nonmetal O (can't decide)arrow_forwardWhat names are given to SiO2 when it exists in the following two solid-state forms? Amorphous Solid Form (alone or mixed with other compounds): Covalent Crystal Form:arrow_forward
- 2. A closed vessel of volume 10.0 L initially contains 1.303 g of water and no water vapor. Please calculate the mass of liquid water remaining once the system reaches equilibrium at 30 degrees Celsius. The vapor pressure of water at that temperature is equal to 0.0418 atm.arrow_forwardWhat are the various phases of SiO2?arrow_forwardThe heat of fusion for actinium is 10.50 kJ/mol. The entropy of fusion for actinium is 9.6 J/mol x K. From this data, calculate the melting point (in oC) of actinium.arrow_forward
- Chemistry: Principles and ReactionsChemistryISBN:9781305079373Author:William L. Masterton, Cecile N. HurleyPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781133949640Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage LearningChemistry & Chemical ReactivityChemistryISBN:9781337399074Author:John C. Kotz, Paul M. Treichel, John Townsend, David TreichelPublisher:Cengage Learning
- Chemistry for Engineering StudentsChemistryISBN:9781337398909Author:Lawrence S. Brown, Tom HolmePublisher:Cengage Learning