A mixture of 0.750 mol H₂ and 0.750 mol I₂ was placed in a 1.00 L flask at 430°C. The equilibrium constant K_c for the reaction is 54.3 at this temperature. Calculate the concentration of H₂, I₂, and HI at equilibrium.

                                    H₂        + I₂           ⇌         2 HI

From an initial mix of: 2 mol Cl2, 1 mol Br2, 1 mol I2, 1 mol Cl−, 1 mol Br−, & 5 mol I−; the total quantity of Br2  present after all possible reactions occur is

give the steps for the enantioselective synthesis of

(L)-tyrosine

and another for (D)-tyrosine

both starting from the corresponding (Z)-enamido acid and using a rhodium as a catalyst

Determine the percent ionization of the following solutions of phenol at 25°C:

(a) 0.795 M

_____%

(b) 0.280 M

_____%

(c) 1.57×10⁻⁶M

_____×10_____%

(Enter your answer in scientific notation.)

From an initial mix of: 2 mol Cl2, 1 mol Br2, 1 mol I2, 1 mol Cl−, 1 mol Br−, & 5 mol I−; the total quantity of Br2  present after all possible reactions occur is

Elemental Composition Problem: Pick one sample of any substance in the world and explain the elements involved with that substance. Do not pick an organic molecule because they are well known to contain C, H, O, and N. (Don't pick a substance such as a plastic water bottle, a human, or a perfume) Describe how you know their compositions.

The value of the universal gas constant is 0.082 (L atm)/(mol K) or 8.31 J/(mol k) and 1.00 atm = 760 mmHg or 760 torr.

When a sample of H_{2​​​​}O_{​​​​​​}​​​​​​₂ is decomposed, 350 mL of O₂ gas is collected at 20 °C and at a partial pressure of 695 torr. How many moles of O₂ gas were collect

The value of the universal gas constant is 0.082 (L atm)/(mol K) or 8.31 J/(mol k) and 1.00 atm = 760 mmHg or 760 torr.

Use the balanced equation for the reaction to determine how many grams of H₂O_2​ were decomposed in the reaction and how many ml of liquid water would be collected upon cooling (assume a density of water of 1 g/ml)?

Which of the following 1M solutions will have the highest concentration of ions?

A) Na₂[CdCl₄]
B) K₃[V(C₂O₄)₃]
C) K₂[MoOCl₄]
D) [Co(en)₂(C₂O₄)]Cl
E) [Zn(en)₂]Br₂

1. Carry out the following calculations, expressing each result with the correct number of significant figures:?

a) 16.421 g + 0.050 48 g = ? g

b) 4.6742 g / 0.003 71 L = ? g/L

c) 0.541 mL + 32.1 mL - 2.5833 mL = ? mL

2. The following cylinder contains three liquids that do not mix with one another:
water (density=1.0g/mL),
vegetable oil (density=0.93g/mL),
and mercury (density=13.5g/mL

-Which liquid is which?
a.Top liquid is?
b. Middle liquid is?
c. Bottom liquid is?

3. What is the mass (in kilograms) of a cube of silver that measures 0.67m on each side? (The density of silver is 10.5 g/cm3?)

1. Sulfanilic acid (NH2C6H4SO3H) has a pKa of 3.23. How many grams of Na(NH2C6H4SO3) [182.1 g/mol] would you have to dissolve in 125 mL of water to get a pH of 7.97?

a. 0.59

b. 1.2g

c. 3.5g

d. 4.8g

2. When KNO2 is dissolved in water, ___________.

3. Calculate the concentration of HCN in a sol’n prepared by dissolving 10.8 g of NaCN (49 g/mol) in enough water to make 500.0 mL of sol’n.  Ka for HCN = 4.0 x 10-10

1. 		0.0057 M
   		0.0033 M
   		0.41 M
   		0.15 M

4. What is the pH of a sodium formate (68 g/mol) solution prepared by adding 0.680 g of sodium formate to 100.0 mL of water at 25°C? The Ka for formic acid is 1.8 x 10-4 at 25°C.

5. Of the compounds below, a 0.10 M aqueous solution of ________ will have the highest pH.

What is the pH of a solution made by mixing 500 mL of 1.00 M HCN and 1.50 L of 0.250 M NaOH, and then diluting the entire solution to a volume of 3.00 L? (Ka HCN = 4.0 x 10^-10)

• A.

  8.92

• B. 6.52

• C.

  9.88

• D.

  9.27

• E.

  5.08

To obtain one litre of a solution of pH = 7, you should dissolve in water

• A.

  Two mol of HI + two mol of CH₃NH₂

• B.

  One mol of H₂SO₄ + two mol of NH₃

• C.

  One mol of HF + one mole of KOH

• D.

  Two mol of H₂SO₄ + four mol of NaOH

• E.

  Two mol of H₃PO₄ + three mol of Ca(OH)₂