1. Would a 50:50 solution of R and S enantiomers of the same compound have any effect on plane polarized light shining through it? Why or why not?

2. Based on your answer to the last question, how could you determine the enantiopurity of a given concentration of a sample if you know its specific rotation [α] using a polarimeter?

3. Give an example of a drug which can be sold as a racemic (R and S) mixture without any harmful effects.

Phosphoric acid is a triprotic acid (K_a1=6.9x10^-8, K_a2 = 6.2x10^-8, and K_a3=4.8x10^-13). To find the pH of a buffer composed of H₂PO₄^- (aq) and HPO₄^2-(aq), which pk_a value would you use in the Henderson-Hasselbalch equation? Calculate the pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L

Calculate the hydronium ion concentration and the pH at the equivalence point when 65.0 mL of 0.4000 M NH3 is mixed with 35.0 mL of 0.7429 M HCl.

Ka=5.6x10-10

Balance the following using the ½ reaction method Permanganate ion plus bromide ion yields (MnO4) and BrO3 - (basic solution)

Describe the process for determining the orbital diagram for an atom, including the number of orbitals and electrons for each subshell. Describe how quantum numbers relate to the orbital diagrams. How does this quantum mechanical view of the atom differ from the Bohr model of the atom?

Part A Suppose that the microwave radiation has a wavelength of 11.6 cm . How many photons are required to heat 275 mL of coffee from 25.0 ∘C to 62.0 ∘C? Assume that the coffee has the same density, 0.997 g/mL , and specific heat capacity, 4.184 J/(g⋅K) , as water over this temperature range.

Express the number of photons numerically.

l

A solution is made by dissolving 0.0500 mol of HF in 1.00 kg of water. The solution was found to freeze at -0.104C. Calculate the percent dissociation of HF in this solution.

Determine the energy of 2.00 mol of photons for each of the following kinds of light. (Assume three significant figures.)

Infrared radiation (1590nm)

Visible light (500nm)

UV radiation (150nm)

How do aqueous solutions of ionic and molecular compounds differ?

Balance these equations for reactions occurring in an acidic solution:

(a) NO₃^–  + Zn --> NH₄⁺ + Zn²⁺

(b) Cr³⁺ + BiO₃^– --> Cr₂O₇^2– + Bi³⁺

(c) I₂ + OCl^– --> IO₃^–  + Cl^–

(d) Mn²⁺ + BiO₃^– --> MnO₄^– + Bi³⁺

What mass (in grams) of nitrogen must be added to 8.34 g of argon at 24.17oC, and in a 126.1 L contain for a final pressure of 895 mmHg?

What is the mole fraction of O2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

What is the mole fraction of N2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

What is the mole fraction of H2 in a mixture of 15.1 g of O2, 8.19 g of N2, and 2.47 g of H2?

What is the partial pressure in atm of O2 of this mixture if it is held in a 15.20 −L vessel at 15 ∘C?