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General Chemistry

PRESSURE

A gas sample containing N2 and O2 was found to contain 72% N2. If the pressure of the sample was 2.0 atm, what is the partial pressure of O2? A. 0.56 ATM B. 0.28 ATM C. 1.44 ATM D. O.72 ATM E. 0.43 ATM

Pressure

The pascal is the SI unit for pressure defined as force (in newtons) per unit area ( in m2). If the force exerted by a gas on a 2.5 square meter area is 8.5 newtons, what is the pressure of the gas in Pa? A. 0.29 B. 0.21 C. 8.5 D. 17 E. 3.4

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

Chemical Bonding: Melting Point

1. Consider the following data: expect a BeF2 molecule to be linear but an SF2 molecule to be angular. Solubility in Water Melting (kg/kg H2O, 25oC) Point (oC) NaF 0.042 988 NaCl 0.357 801 NaBr 1.16 755 Nai 1.84 651 a) Explain the decreasing melting point from NaF to Nai. b) Explain th

Chemical Bonding

1. Consider you would expect a BeF2 molecule to be linear but an SF2 molecule to be angular. 2. a) How would you designate the hybrid orbitals formed by "mixing" one d one s and two p orbitals? b) How many of the hybrid orbitals would be formed by the mixing? 3. Explain why C20H40 is a solid at 25oC, while C4H8 is a gas

Descriptive Chemistry

1.Write equations for the neutralization reactions that result in the formation of the following salts: a) lithium carbonate b) copper (II) chlorate c) aluminum sulphate d) ammonium iodide 2.For each of the following situations, identify those for which a reaction is likely to occur. For those that do occur, write a net

Molecular Formulas of Different Compounds

1. A compound containing titanium (Ti) and chlorine is analyzed by converting all the titanium into 1.20g of TiO2 and all the chlorine into 6.45g of AgCl. What is the simplest formula for the original compound? 2. Estrone is a female sex hormone that is known to contain 80.0% carbon, 8.2% hydrogen, and the remainder oxygen. I

Chemistry language

Can you please assist me with these problems? 1.Write the correct formula for each of the following manganese (II) iodine 2. Write the correct formula for each of the following ions flourate 3. Name the following compounds: a) BaHPO3 b) AgIO 4. Balance the following equations: i)PbCl2+AgNO3 → AgCl+

Chemistry Questions: Gases and Gas Reactions

A balloon contains 400cm3 of helium at 25 degrees and 1 atm pressure. If the balloon bursts when the volume exceeds 800cm3: a) What would be the maximum temperature it could withstand at constant pressure? b) What would be the minimum pressure it could withstand at constant tempersture? c) What height above sea level would

Food Chemistry and Reactions

1. What unusual aspect of water is responsible for it unique characteristics as both a liquid and as a solid? Give examples of how this property of water would affect food systems during processing. 2. The value of ∆G tells use what about chemical reactions? Give three situations and examples. 3. Chemical potential (μi)

Chemistry Notation Questions

A) Provide the type of measurement (volume, length, temperature etc.) for the following units: i) 298 K ii) 65 mL iii) 15 m iv) 290 kg v) 50 g b) Write the following measurements in scientific notation: i) 150000000 kg ii) 0.28 L iii) 0.00004 m c) Answer wheth

Lewis Structures and VSEPR (valence shell electron pair repulsion)

Lewis Structures and VSEPR (valence shell electron pair repulsion). See attached file for full problem description. 1. Listed in the attached document are electron dot formulas for several simple molecules and ions. All valence electrons are shown; however, electrical charges have been omitted deliberately. Which of the

Half Life Homeowrk Problems

Is there just one formula to calculate half life problems? What is the process or formula for solving these problems. 1. A 2.5 gram of an isotope of stontium-90 was formed in a 1960 explosion of an atomic bomb at Johnson island inthe Pacific test Site. The half -life of strontium-90 is 28 years. In what year will only .625

Nuclear equations: Example problems

8. Show that for this nuclear equation, the sum of the subscripts on the left is equal to the sum of the subscripts on the right . Then show that the sum of the subscripts on the left is equal to the subscripts on the right 239 94PU + 4 2He---> {243 96 Cm} --->242 96 Cm + 1 On 9.When 4.oo g of hydrogen nuclei fuse to form he

Lewis Structure Hybridization

4. The molecule pictured below is AZT. It is a widely used drug for the treatment of AIDS. The Lewis structure below is complete except for electron lone pairs. For this structure: a. Draw in all missing electron lone pairs. b. Write in the shape of the molecule at the atoms indicated by arrows attached to boxes with "shap

Sigma (σ) and pi (π) bonds

1. How many sigma (σ) and pi (π) bonds are in each of the following molecules? Molecule Number of σ bonds Number of π bonds Molecule Number of σ bonds Number of π bonds CO2 XeF3+ N2 Cl2CO CO32- ion BrO3_ 2. An iron atom is located in a molecule called an "iron-porphyrin" (or "heme") which has an import

Oil Drop Experimental Units

Please show how to solve the following problem: Repeat Millikan's oil drop experiment using a unit of your own devising (B) rather than the unit of Coulombs. You measure the charges on 4 different drops labeled a, b,c, d. You determine that drop a has charge 13.52 B, drop b has charge 3.359 B, drop c has charge 10.21 B, and

Valance Bands & Energy to Produce and Electron Hole Pair

3. A material has an effectively full valence band and an empty conduction band. Explain why that if these two bands overlap the material behaves as a metal and if they are separated by a few electron volts in energy the material is an insulator. 4. Calculate the minimum energy a photon must have to produce an electron hole p

Clinical Uses of Radioactivity & Decay

How long would it take for a radioactive isotope with a half life of 2 weeks to lose at least 70% of its radioactivity? Describe two clinical uses of Radioactivity.

Pressure Using a Manometer

An open-end manometer containing mercury is connected to a container of gas. The mercury in the arm attached to the gas is 13.6cm higher than the one open to the atmosphere. The atmospheric pressure is 1.05atm I have to find the pressure of the enclosed gas in torr.

MO theory and dissociation energy

Use simple MO Theory (LCAO-MO) to explain why the dissociation energy of neutral N2 is greater than the N2+ ion, but that the dissociation energy of the O2+ ion is greater than the O2 neutral.

AP Chemistry: Test Review

(See attached file for full problem description) --- I need full explanation of each step. Please help. 1. The helium ion, He+, has energy levels similar to those of the hydrogen atom, since both species have only one electron. The energy levels of the He+ ion are given by the equation En = - 5248.16 kj/mole n =

Percentage yields

A chemist isolates 17.43 g of product from a reaction that has a calculated theoretical yield of 21.34 g. What is the percentage yield?

Wavelength and Frequency Example Problem

Question 1: M. tuberculosis, the organism that causes tuberculosis, can be completely destroyed by irradiation with UV light with a wavelength of 254 nm. What is the frequency? Question 2: Aradio station's signal broadcasts at a freq. 1240kHZ. What is the wavelength in meters?

Distinguish Ionic or Covalent Bonding

While you are working in the lab your instructor hands you a vial of red, crystalline material and asks you to tell if it has ionic or covalent bonding. Describe at least one experiment you would do to answer the instructor's question.

Volatility

Suppose you were given samples of two different liquids. Describe how you would determine which one is more voliatile.

Conversions

The volume of a certain bacterial cell is 1.60 µm3. (a) What is its volume in cubic millimeters (mm3)? (b) What is the volume of 105 cells in liters (L)? [show all the conversion factors that were used in calculating the answers]

Particle in a Box Proportionality

A particle is constrained to lie along a one-dimensional line segment between 0 and a. The probability of finding the particle along this line segment is seen in attached file. A. Find the proportionality constant, ie., normalize the function. B. Calculate the expectation values of X and X^2 for n=1 and n=2. C. Find t