3. Study dehydration synthesis and hydrolysis. Why are these reactions called dehydration synthesis if dehydration means to remove water and synthesis means to build? What do you think happens to large molecules during hydrolysis reactions?

A materials scientist has created an alloy containing aluminum, copper, and zinc, and wants to determine the percent composition of the alloy. The scientist takes a 12.232 g sample of the alloy and reacts it with concentrated HCl. The reaction converts all of the aluminum and zinc in the alloy to aluminum chloride and zinc chloride in addition to producing hydrogen gas. The copper does not react with the HCl. Upon completion of the reaction, a total of 10.1 L of hydrogen gas was collected at a pressure of 739 torr and a temperature of 27.0°C. Additionally, 2.797 g of unreacted copper is recovered. Calculate the mass of hydrogen gas formed from the reaction. mass: g Calculate the mass of aluminum in the alloy sample. mass: g What is the mass percent composition of the alloy? Cu : % Zn : % Al : %

Name and describe at least two instruments that can detect trace amounts of metal elements in a sample.

In addition to maintaining pH, another important consideration when generating a buffer is the ionic strength of a buffer. The ionic strength refers to the number of ions in a solution. Ions help to increase the solubility of species in a solution. How would ions increase the solubility of species in a solution? If the ionic strength of a solution is too high, the species in the solution precipitate. Why?

Draw the Lewis structure for CH2MgBr and give the formal charge of each atom

Explain why one can obtain eigenfunctions for the Hamiltonian operator for the H atom, but can only obtain approximate wavefunctions for multi-electron atoms.

If a buffer solution is 0.160 M in a weak acid (Ka = 1.0 × 10-5) and 0.470 M in its conjugate base, what is the pH?

State the Born-Oppenheimer approximation and describe how its use simplifies the description of Hamiltonian operator for quantum chemical calculations. [4 Marks]

By describing the underlying principles of Hartree-Fock theory and density functional theory, briefly compare and contrast the two methods.

Is there any other way we could obtain the concentration of the protein fractions other than using Bradford assay?

(Hint: Fluorescent proteins)

1.) Determine the initial concentration of a solution of the weak acid HClO2 , if it its pH is 1.20 and Ka = 1.10

Sulfurous acid (H₂SO₃) has K_a1 = 1.500 × 10^-2 and K_a2 = 1.000 × 10^-7. Consider the titration of 60.0 mL of 1 M sulfurous acid by 1 M NaOH and answer the following questions.

What is the maximum number of protons that can sulfurous acid ionize (per molecule)?

b) Calculate the pH after the following total volumes of NaOH have been added. (Correct to 2 decimal places.)   No marks will be given if the number of decimal places is wrong.

i. 0.0 mL of NaOH  

ii. 30.0 mL of NaOH  

iii. 60.0 mL of NaOH  

iv. 90.0 mL of NaOH

v. 120.0 mL of NaOH

vi. 130.0 mL of NaOH

The reaction of methane with water to form carbon dioxide and hydrogen is
non-spontaneous at 298 K. Use the thermodynamic data from the table (it refers to 298 K) and determine at which temperature the system will make the transition from non-spontaneous to spontaneou

Substance:   CH4(g)    H2O(g)   CO2(g) H2(g)

ΔH° f (kJ/mol):   -74.87   -241.8    -393.5 0

ΔG° f (kJ/mol):   -50.81 -228.6 -394.4 0

S°(J/K·mol):   186.1     188.8   213.7 130.7