Homework Help for Chemistry

PROBLEMS FOR PRACTICE

1. What is the energy in kcal of one mole of photons of 2573 A wavelength?

2. Calculate the energy of one photon of light of 2450 A wavelength. Will it be able to dissociate a bond in a diatomic molecules which absorbs this photon and has a bond energy equal to 95 kcal per mole?
Planck’s constant (ft) = 6.626 • 10*27 erg s molecule*1 Velocity of light (c) = 3 • 1010 cm sql

Avogadro’s number (N) = 6.02 • 1023
flint: Calculate the energy of the photon. If this energy is greater than that required to break the bond (bond energy), dissociation of the bond will happen.

3. Calculate the value of an einstein of energy in electronvolts for a radiation of 3 • 101S sql
frequency.

4. Calculate the value of the einstein corresponding to radiation of 6000 A wavelength.

5. Find the value of an einstein of energy for radiation of 4240 A wavelength.

4. If a 2 mm thick plate of material transmits 70% of the incident light, what percentage will be transmitted by a 0.5 mm thick plate?

1. 3. The percentage transmittance of an aqueous solution of disodium fumarate at 250 mm and 298 K is 19.2% for a 5 • 10“ molar solution in a 1 cm cell. Calculate the absorbance A and the molar absorption coefficient e. What will be the percentage transmittance of a 1.75 • 10’S molar
   solution in a 10 cm cell?
   [An s. A -  0.717, -  1.43 •  io 3 L mol*1 cmm l , T -  56.1%]

1. Please send me questions about ECAT test
2.  

Questions 1-5 solve please

boyles law chemistry

Determine the percentage of ionization of a 0.15 M benzoic acid solution in clean water and a 0.10 M sodium benzoate solution. Why does the % ionization in the two solutions vary so widely?

Complete Electron Configuration or Extended Configuration

At atomic number greater than 18, the sublevels begin to fill out of order. A good approximation can be made by using the periodic table as a templet and knowing that transition metals (d sub-level) are one energy level less than their period. Additionally, the inner transition metals (f sub-level) are two energy levels less than their period.

Write the complete electron configuration for the following elements on the FICTIONAL PERIODIC TABLE.

5. Solarium

6. Vibranium

7. Clownium

8. Galvorn

9. Tiberium

Draw the arrow diagram electron configuration for ALL of the following elements from the FICTIONAL PERIODIC TABLE and use it to answer the following questions about each element.

11-15: Calculon,Nucleon, Afraidium, Onionium, and Fazon.

Draw the arrow diagram above then use it to answer the following

For the highest occupied sub level:

a. How many 1/2 filled orbitals

b. How many filled orbitals

c. How many empty orbitals

Calculate the temperature at which air possesses density equally to that of Hydrogen at 0°C.Density of air at NTP: 14.4.

Consider a small system that is interacting with a reservoir at temperature 400 K, pressure 108 Pa, and chemical potential ‒0.3 eV.

(a) To go from state 1 to state 2, the small system must take an additional 0.03 eV of energy and 10‒29 m3 of volume from the reservoir. How many times more probable is it for the small system to be in state 1 than state 2?

(b) To go from state 1 to state 3 the small system must take 0.4 eV of energy and one particle (but no extra volume) from the reservoir. How many times more probable is it that the small system is in state 1 than state 3?

(c) To go from state 1 to state 4, the small system must take no energy but one particle and 10‒27 m3 of volume from the reservoir. How many times more probable is it that the small system is in state 1 than state 4?

Determine the energy change for the following reaction 

Methane + oxygen produces carbon dioxide + water 

Determine the energy change for the following reaction:

Methane + oxygen produces carbon dioxide + water.

What is copper

A chemist prepares a solution of silver (I) pre-chlorate(AgCIO4) by measuring out 4.2×10^2 umol of silver pre-chlorate into a 350 mL volume metric flask and filling the flask to the mark with water. Calculate the concentration and umol /liters of the chemists silver plate chlorate solution, be sure your answer has the correct number of significant digits