Consider the equilibrium shown.

PbBr2(s)−⇀↽− Pb2+(aq)+2Br−(aq)Ksp=2.10×10−6

Determine the concentrations of Pb2+ and Br− in a saturated solution of PbBr2 in pure water (assume μ=0 M).

[Pb2+]=

M

[Br−]=

M

Determine the concentrations of Pb2+ and Br− in a saturated solution of PbBr2 in a solution with an ionic strength of 0.010 M.

[Pb2+]=

M

[Br−]=

M

Determine the concentrations of Pb2+ and Br− in a saturated solution of PbBr2 in a solution with an ionic strength of 0.10 M.

[Pb2+]=

M

[Br−]=

Does gelatin contain tyrosine? How do you know?

What is the molality of a solution of naphthalene in benzene if the freezing point of pure benzene is 5.5°C and the freezing point of the solution is 4.0°C. The freezing point depression constant for benzene is 5.12°C m-1.

Which compound has the smallest molecular weight? A. Al(OCH3)3 B. Ga(OCH3)3

C. B(OCH3)3 D. (BO(OCH3))2

Crossword

ACROSS 1. Spectrum of the specific wavelengths at which compounds absorb

3. In Beer Lambert’s Law __________ is proportional to absorbance.

4. Spectrum with wavelength lower than 340nm

9. The ________ in a spectrometer captures light and outputs an electrical signal.

10. Where a specific factor is not known, the concentration of a sample can be determined through constructing a __________ curve by measuring the Absorbance of standards that contain known concentrations of the analyte.

11. ________ is measured in the dimensionless unit, AU.

DOWN 2. A graph showing how light from a sample source varies with wavelength.

5. Spectrum with wavelength higher than 750 nm

6. In Beer Lambert’s Law e is the _________ COEFFICIENT

7. designed to hold samples for spectroscopic experiments

8. Spectrum with wavelength in range of 340 - 750 nm

Discuss the advantages and drawbacks of the open molding method in thermoset composite processing.

5. Describe various types of emulsions and how to identify them?

6. How come emulsion can increase the solubility of hydrophobic molecules?

For all cycles in this section, assume that you have exactly 1.000 moles of gas and that the cycle is run reversibly. The known state parameters for the cycle will be given as the reduced temperature T_r ≡ T /T_c and reduced pressure P_r ≡ P/P_c, where T_c and P_c are the critical temperature and pressure of your assigned diatomic molecule, N₂. Assume the gas is a diatomic van der Waals gas.

You have an Ericsson cycle that begins with an isothermal expansion from an initial state of T_r = 1.75 and P_r = 2.00 to a pressure of P_r = 1.75. The system then undergoes isobaric expansion to a temperature of T_r = 2.00, followed by isothermal compression and then isobaric compression back to the initial state. Calculate w, q, ∆U, ∆S, ∆Ssur, ∆H, ∆A and ∆G for each step in the cycle and for the total cycle.

(entropy S, enthalpy H, Gibbs energy G, and Helmholtz energy A)

Determine whether the following molecules are polar or nonpolar: (a) NBr₃ (b) OCS  (c) XeF₄

In the (Bomb Calorimetry) experiment, 1.10 g of anthracene (C₁₄H₁₀) was burned in a constant volume bomb calorimeter. The temperature of water rose from 20.28 °C to 24.05 °C. If the heat capacity of the bomb plus water was 10.17 kJ/°C: In the (Bomb Calorimetry) experiment, 1.10 g of anthracene (C₁₄H₁₀) was burned in a constant volume bomb calorimeter. The temperature of water rose from 20.28 °C to 24.05 °C. If the heat capacity of the bomb plus water was 10.17 kJ/°C:

-Calculate Δ_c.mH at 25°C

-Why excess oxygen was used in this experiment? Why not using ambient air?

How many grams of urea [(NH2)2CO] must be added to 400 g of water to give a solution with a vapour pressure 2.50 mmHg less than that of pure water at 30°C? (The vapour pressure of water at 30°C is 31.8 mmHg.)

A solution of ethanol CH3CH2OH and water that is 10.% ethanol by mass is boiling at 98.7°C. The vapor is collected and cooled until it condenses to form a new solution.

Calculate the percent by mass of ethanol in the new solution. Here's some data you may need:

Be sure your answer has the correct number of significant digits.

Note for advanced students: you may assume the solution and vapor above it are ideal.

Write down the series of oxygen-only chemical reactions relating to the formation and destruction of ozone in the stratosphere. Describe the role of each individual reaction and indicate how Chapman could use them to explain the existence of a stratospheric ozone “layer”.

Describe what is meant by the term “greenhouse effect”. Indicate which species make the greatest contribution and describe their natural and manmade sources. Explain why the major components of air are ineffective greenhouse gases.

In a 4.50L sealed, evacuated flask, Robert injected 2.25g of liquid water and then heated it up to 50.0°C, while measuring the p inside. When the system stabilised, p total = 196.0mmHg. What percentage of water remains as liquid in the flask?