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General Chemistry

Net Ionic Equation

Zinc is reacted with lead nitrate. Balance equation and write net ionic equation.

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

Paramagnetic Elements

Which of the following species would you expect to be paramagnetic? Briefly explain the answers using molecular orbital energy level diagrams or molecular orbital electron configurations. N2, N2-, N2+, O2, N2^2- O2+, O2-, O2^2-

Ionic Formulas Completed

Complete the chart by filling in the correct ionic formulas. Cl- OH- O2- SO42- CO32- PO43- Na+ NH4+ K+ Ba2+ Ca2+ Mg2+ Fe2+ Cu2+ Al3+ Fe3+

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.

Degrees of freedom of a saturated solution

A saturated solution of Na2SO4 with excess of the solid is present in equilibrium with its vapor in a closed vessel. Calculate the number of degrees of freedom, f, of the system. Ignore the autoprotolysis of water and assume that the salt solvates without ionizing. F = c - p +2 or use f = c-p +2 -r -a c = chem species

Calculate the Number of Moles

A steel tank with a volume of 9.583 L contains N2 gas under a pressure of 4.972 atm at 31.8 °C. Calculate the number of moles of N2 in the tank.

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?

Chemical Symbol Elements

Give the name and chemical symbol for: a) An element with 50 electrons b) An element with 28 protons c) An element with 2 electrons in the first shell, 8 electrons in the second shell, 8 electrons in the third shell, and 2 electrons in the fourth shell d) An element with atomic number of 78

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.

Compound or a mixture?

Tell whether the following is a property of a compound or a mixture: a) Can contain three elements in a specific ratio b) Varies in chemical composition depending on the sample size c) Can be classified as either homogeneous or heterogeneous

Heterogeneous and homogeneous mixture

Tell if the mixture is homogeneous or heterogeneous and explain why you classified it as homogeneous or heterogeneous. a) Iced tea b) Salad c) Chocolate chip cookie