Organic Chemistry Answers

what is Nernst equation ?write its application

Determine (OH), ph and pOH of a solution [H]+ with 2.5 X 10 -8 M

1. An unknown compound containing C, H, N, and O elements in different multiples of the empirical formula. Using the data contained in the table, find me a) the empirical formula, and b) the molecular formula of a family member with a molar mass of 390 g/mol. 

Element Percent Composition (%) Molar Mass (g/mol)

C 36.9 12.01

H 6.2 1

N 32.3 14

O ? 16

NO2CH=CHCH3 + HBr

[a] Calculate the percentage of both the axial and equatorial forms of methylcyclohexane. Assume T = 25 °C. [b] Draw the equilibrating chair conformers. [c] Reading from the left to the right, is the equilibrium you’ve just illustrated representative of an exergonic or an endergonic process? [d] Based upon the response to part ‘c’, will ΔG be positive or negative? [e] Highlight the 1,3-diaxial interactions present in axial conformer.

Find the pka value of the following.

For the reaction below:

Zn(s) + PbSO4(aq) = Pb(s) + ZnSO4(aq)

a) Write a balanced net ionic equation for the reaction.

b) Identify which reactant is oxidized and which one is reduced.

c) Identify which reactant is the oxidizing agent and which one is the reducing agent.

d) Write balanced half reactions for the oxidation and reduction.

1. In a galvanic cell is the anode the positive or negative electrode? 

2. What is the direction of electron flow in the external circuit of a galvanic cell? 

3. If aluminum and tin were used as the electrodes in a galvanic cell which metal would be the anode and which metal would be the cathode. Explain why.

7. Hydrogen fuel cells:

a) Are recharged by plugging them into an electrical outlet.

b) are recharged by filling the cell up with fuel, similar to filling up a gas tank.

c) cannot be recharged.

d) are recharged by using electricity to reverse the chemical reactions that occurred in the cell.

8. The following substance(s) must be present for the corrosion of iron to occur.

a) oxygen and carbon dioxide

b) water and carbon dioxide

c) oxygen and water

d) oxygen

9. In the redox reaction of the corrosion of iron which substance is reduced?

a) iron

b) oxygen

c) iron(III) oxide

d) water

10. Generally which of the following factors decreases the rate of iron corrosion?

a) the presence of salt.

b) contact with a more reactive metal

c) acidic conditions

d) mechanical stress, such as bending

4. The cathode is:

a) the negative electrode where reduction takes place.

b) the positive electrode where reduction takes place.

c) the negative electrode where oxidation takes place.

d) the positive electrode where oxidation takes place.

5. In a Daniell cell with a zinc anode the positive charge that builds up in the zinc half-cell is neutralized by:

a) positive ions migrating towards the anode.

b) negative ions migrating towards the cathode.

c) negative ions migrating towards the anode.

d) positive zinc ions, Zn2+, being reduced to produce zinc atoms.

6. Which of the following types of batteries can be recharged?

a) alkaline dry cells

b) zinc chloride

c) nickel-cadmium (Ni-Cad)

d) mercury button battery