You are given a sample of several compounds to separate by paper chromatography. You draw a pencil line exactly 1.0 cm from the bottom of the paper, and place a spot of sample on it. You dry the sample, then develop it in a solvent.

When the chromatogram is taken out of the solvent, the paper is wet up to 9.0 cm from the bottom of the sheet. The compound you are interested in shows up as a spot 7.3 cm from the bottom of the paper.

Calculate the following:

How far did the compound move?

In the same time, how far did the solvent move?

What is the Rf factor for the compound?

Predict the following to be primary secondary or tertiary: Hexane if insoluble in water. 1-Hexene if insoluble in water but tests positive for a Br2 test. 1-bromobutane if insoluble in water but tests positive for a AgNO3. Ethanol and cyclohexane if they both tests postive for a Lucas test. and finally Ether if it tests negative for a Lucas test.

Write the electron configurations for the following ions, and determine which have noble-gas configurations.

A) Ru ³⁺   B) As^3-   C) Y³⁺  D) Pd²⁺   E) Pb²⁺ F) Au³⁺

When 1.90 mol CO2 and 1.90 mol H2 are placed in a 3.00-L container at 395 ∘C, the following reaction occurs: CO2(g)+H2(g)⇌CO(g)+H2O(g).?

Part A
If Kc = 0.802, what are the concentrations of CO2 in the equilibrium mixture?
Part B
If Kc = 0.802, what are the concentrations of H2 in the equilibrium mixture?
Part C
If Kc = 0.802, what are the concentrations of CO in the equilibrium mixture?
Part D
If Kc = 0.802, what are the concentrations of H2O in the equilibrium mixture?

During a titration, a student used 31.92 ml of a .1000 M NaOH (aq) to neutralize 30.0 ml of a . 2488 M oxalic acid solution.

1. Consider the following reaction:

3CH4(g)→C3H8(g)+2H2(g)

Calculate ΔG at 298 K if the reaction mixture consists of 41 atm of CH4, 0.011 atm of C3H8, and 2.1×10⁻² atm of H2.

Express the Gibbs free energy in kilojoules to two significant digits.

2. The element gallium (Ga) freezes at 29.8 ∘C, and its molar enthalpy of fusion is ΔHfus = 5.59 kJ/mol.

Calculate the value of ΔS when 61.0 g of Ga(l) solidifies at 29.8 ∘C. in J/K

What is the molar solubility of Fe(OH)₃ in a solution buffered at pH = 4.52? (See the appendix.)
M

What is the molar solubility at pH = 8.16?
M

A sample of ammonia gas is completely decomposed to nitrogen andhydrogen gases over heated iron wool. If the total pressure is 639mmHg, calculate the partial pressure of N2 and H2. Enter your answers in scientific notations

Consider 25 ± 1 (n=5) and 26 ± 1 (n=6); The uncertainty listed is the standard deviation. Are these two measurements significantly different at the 95% confidence limit ?  

If 4.90 g of CuNO3 is dissolved in water to make a 0.850 M solution, what is the volume of the solution?

Identify the following statements as true or false. (Use the drop-down menu and select "True" or "False" for each. You must get all 6 correct.)
1. The entropy of the universe is constant; the energy of the universe decreases towards a minimum.
2. If a reaction is spontaneous, the reverse reaction is non-spontaneous.
3. If a process decreases the randomness of the particles of a system, the entropy of the system decreases.
4. Both ΔS_sys and ΔS_surr must equal zero at equilibrium.
5. All systems become more disordered spontaneously.
6. The boiling of water at 105°C and 1 atm is a spontaneous process.

12. 175 g of Fe at 15.0oC is mixed with 225 g of H2O at 95.0oC. What is the final temperature of the mixture? The specific heats of iron= 0.448 J/g oC and water = 4.184 J/g oC). (keep in mind the following: heat gained + heat lost = 0 and q=mass x heat capacity x T)