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General Chemistry

Explanation of melting point & boiling point deviations

I only need help on question 3. I have perfomed the labs for melting pt and boiling pt on the following four and only need help with question 3 acetonitrile (C₂H₃N): GIVEN MP = -45.5C, BP = 77.3C My results MP= -46.8 C, BP = 79.4 C benzene (C6H6) GIVEN

Molar solubility product of barium fluoride

Please help with the following problems. Provide step by step calculations for each. 5.[a] The molar solubility of barium fluoride, BaF2, is 7.5 x 10-3 M. Calculate the solubility product constant [b]Calculate the molar solubility of lead fluoride, PbF2 in water, Ksp = 2.7 x 10-8 6.Calculate the molar solubility of bism

PowerPoint Presentation on the Element Boron

BORON I am looking for someone who is knowledgeable with PowerPoint. I need help getting started with this project and knowing how to go about this. My classmates told me finding a scientific article is the hard part to this project, so I want someone to help me with that also. _______________________________________

Neutralization

What volume of 0.101 M HNO3 is required to neutralize 23.7 mL of 0.00517 M Ba(OH)2 mL

Finding Molar Concentration

You have a 50 µM solution of sodium phosphate. Express this as a molar concentration, as a millimolar concentration.

General Chemistry Problems

10.40) Many gases are shipped in high-pressure containers. Consider a steel tank whose volume is 65.0L and which contains O2 gas at a pressure of 16,500kPa at 23°C. a. What mass of O2 gas does the tank contain? b. What volume would the gas occupy at STP? c. At what temperature would the pressure in the tank equal 150.0atm? d. W

Assorted General Chemistry Problems

8.20) a. The lattice energies of NaF and MgO are 910kJ/mol and 3795kJ/mol. Account for the difference in these two quantities. b. Account for the difference in lattice energies of MgCl2 (2326 kJ/mol) and SrCl2 (2127kJ/mol). 8.28) Calculate the lattice energy of CaCl2. Is this value greater than or less than the lattice energ

General Chemistry Problems

5.38) Consider the following reaction: CH3OH (g) ---> CO (g) + 2 H2 (g) deltaH = +90.7 kJ a. Is heat absorbed or evolved in the course of this reaction? b. Calculate the amount of heat transferred when 45.0 g of CH3OH (g) is decomposed by this reaction at constant pressure. c. For a given sample of CH3OH, the enthalpy change

Assorted General Chemistry Problems

1.28) a. A cube of osmium metal 1.500cm on a side has a mass of 76.31g at 25°C. What is the density in g/cm3 at this temperature? b. The density of titanium metal is 4.51g/cm3 at 25°C. What mass of titanium displaces 65.8mL of water at 25°C? c. The density of benzene at 15°C is 0.8787g/mL. Calculate the mass of 0.1500L of be

Calculate the deBroglie Wavelength

Calculate the "deBroglie wavelength" for each of the following: 1. an electron moving at 0.82 times the speed of light...... in meters 2. a 125-g ball moving at a speed of 13.6 m/s.....in meters 3. a 61-kg person walking at a speed of 2.00 km/hr....in meters These answers explain why macroscopic (large) objects a

Solving 7 Chemical Equations

I desprately need help solving these chemical equations to help me to study for an exam. Rules for Solving Chemical Equations: 1. Write the chemical reaction in word form 2. Post your symbols 3. Post diatomics (for single units only) 4. Post oxidation numbers for compounds 5. Post subscription (for compounds onl

Assorted General Chemistry Problems

1) Given the following data table of average bond enthalpies, estimate the ΔH^rxn for the reactions 2H2+O2-- 2H2O Bond Average (kJ/mol) H-H 436 O=O 498 H-O 423 2) Draw eight distinct, valid Lewis resonance structures for the molecule XeO3. 3) Which structure or structures is or are mo

Assorted General Chemistry Problems

1) List the following gases in order of increasing root-mean-square speed, all at the same temperature: H2, He, O2, Ne 2) Under what conditions of pressure and temperature is a real gas most expected to deviate from ideal gas behaviour? 3) What intermolecular interactions would be the strongest between molecules CH2Cl2?

Molecular Geometry and Bond Order Problems

1) What is the molecular geometry of the ammonium ion? 2) What is the molecular geometry of the SO2Cl2 molecule? 3) What is the approximate F-S-F bond angle in sulfur hexafluoride? 4) What is the hybridization of the central atom in COCl2? 5) What is the hybridization of the central atom in selenium tetrabromide?

Light and Quantum Numbers

1) What is the molar concentration of a solution that is made by dissolving 6.30g of sodium chloride and diluting 1.00L?Report your answer to three significant figures. 2) In an experiment, 6.00g of Mg(s) was reacted completely with O2(g) to form MgO(s) and 148.5kJ of heat was evolved. What is the molar emthalpy of formation

Assorted General Chemistry Problems

1) In a combustion analysis, 2.00mg of vitamin C yielded 3.00mg CO2 and 0.816mg H2o. From mass spectrometry, it was found that the molecular weight of vitamin C is 176amu. Determine the mass composition of vitamin C, its empirical formula, and its molecular formula. 2) What is the energy of the photon that is emitted when the

Frequency and wavelength

Excited mercury atoms emit light strongly at a wavelength of 436 nm. What is the frequency of this radiation?

Radius/Density From bcc and fcc Unit Cells

Krypton crystallizes as a fcc (face centered cubic unit cell) having an edge length of 559 pm. (a.)What is the density of solid Krypton? (b.) What is the atomic radius of a krypton atom? (c.)What is the volume of one krypton atom? Potassium crystallizes in a bcc (body centered cubic unit cell) structure. The atomic radi

Fission and isotopes

1a.) You have 16 electrons, 16 protons, and 16 neutrons. You can combine them to make 8 Helium (He-4) atoms, 4 beryllium atoms (Be-8), 2 oxygen atoms (O-16), or one sulfur atom (S-32). What will you do to make the most stable product? Info: H-1 1.00782505 amu He-4 4.0026033 amu Be-8 8.0053052 amu O-16

Chemistry Expressions

1. (a) Express 50 days in seconds (b) Convert 3.75 meter/sec to km/hr. Express the results in scientific notation. 2. Perform the following operations and express the answer with the appropriate number of significant figures. 863[1255-(3.45*10.8)] 3. The recommended dose of Elexophyllin (a drug used to treat

[Pb 2+] and [I-]

If a small sample of pure PbI2 is shaken with water to produce a saturated solution, What must be the relationship between [Pb 2+] and [I-] in that solution? Refer to equation below. PbI2 (s) <--> Pb^ 2+ (aq) + 2I (aq)

Density

What is the pressure, in atmospheres, that is exerted on a diver at a depth of 166 M? Assume the density if water is 1.00g/mL. A. 0.218 B. 12.2 C. 1720 D. 0.0161 E. 16.1

Value of Kb

The [OH-] = 1.3 x 10^ -6 M for a 0.025 M solution of a weak base. Calculate the value of Kb for this weak base. a) 5.2 x 10 ^ -5 b) 3.1 x 10 ^ -7 c) 7.7 x 10 ^ -9 d) 4.0 x 10 ^ -8 e) 6.8 x 10 ^ -11

Packing of Particles in Solids-space Lattices

Hexagonal Closet Packaging vs. Cubic Closet Packaging (face-centered) vs. Body-centered a) Which of the three types of packaging has the least efficient arrangement of atoms? Justify the answer. b) How do the two more efficient forms of packing compare regarding volume? c) What is the relationship between coordination n