What are two factors that a GC column uses to separate compounds?

1)For each of the following reactions, calculate ΔH∘rxn, ΔS∘rxn, and ΔG∘rxn at 25 ∘C.

3H2(g)+Fe2O3(s)→2Fe(s)+3H2O(g)

N2(g)+3H2(g)→2NH3(g)

2)Before investigating the scene, the technician must dilute the luminol solution to a concentration of 6.00×10⁻²M . The diluted solution is then placed in a spray bottle for application on the desired surfaces.

How many moles of luminol are present in 2.00 L of the diluted spray?

3)A student placed 11.0 g of glucose (C6H12O6) in a volumetric flask, added enough water to dissolve the glucose by swirling, then carefully added additional water until the 100. mL mark on the neck of the flask was reached. The flask was then shaken until the solution was uniform. A 55.0 mLsample of this glucose solution was diluted to 0.500 L. How many grams of glucose are in 100. mL of the final solution?

4)A sugar crystal contains approximately 1.4×10¹⁷sucrose (C12H22O11) molecules.

5)When solutions of silver nitrate and potassium chloride are mixed, silver chloride precipitates out of solution according to the equation

AgNO3(aq)+KCl(aq)→AgCl(s)+KNO3(aq)

a)What mass of silver chloride can be produced from 1.17 L of a 0.122 M solution of silver nitrate?

b)The reaction described in Part A required 3.39 L of potassium chloride. What is the concentration of this potassium chloride solution?

5)Consider the precipitation reaction: Li2S(aq)+Co(NO3)2(aq)→2LiNO3(aq)+CoS(s)

a)What volume of 0.160 M Li2S solution is required to completely react with 125 mL of 0.160 M Co(NO3)2?

6)What is the minimum amount of 6.8 M H2SO4 necessary to produce 27.3 g of H2 (g) according to the following reaction? 2Al(s)+3H2SO4(aq)→Al2(SO4)3(aq)+3H2(g)

7)Consider the precipitation reaction: 2Na3PO4(aq)+3CuCl2(aq)→Cu3(PO4)2(s)+6NaCl(aq)

a) What volume of 0.180 M Na3PO4 solution is necessary to completely react with 87.1 mL of 0.122 M CuCl2?

A buffer that contains 0.18 M of an acid, HA and 0.49 M of its conjugate base A-, has a pH of 3.71. What is the pH after 0.041 mol of HCl are added to 0.79 L of the solution?

. List ALL of the intermolecular forces that are present in each element or compound. a. N2 b.PH3 c. NF3 d. XeF2

Given a water sample with the following concentrations, calculate the hardness in meq/L and mg/L as CaCO₃

Ca²⁺= 17 mg/L

CO₃^2-= 3.4 mg/L

1)this question concerns 2-bromobutanoic acid CH₃^aCH₂^bCBrH^cCOOH^d

^{a. for each group of protons (}H^aH^bH^cH^{d) state the splitting pattern you would expect to see (assume splitting is only due to neighboring protons)}

^{B. sketch the carbon-13 nmr (without looking it up). clearly assign each peak.}

^{2) what are shim coils in NMR and what is their purpose?}

^{3) what is the absorption frequency in a 2.4 T magnetic field?}

^a)1H   B) ¹³C C)¹⁹F    D) ³¹P

20.0mL of 0.127M diprotic acid (H2A) was titrated with 0.1018M KOH. The acid ionization constants for the acid are Ka1=5.2

Which one of the following alcohols will be soluble in water? Which one of the following alcohols will be soluble in water? 2-pentanol 2-butanol 3-hexanol 2-propanol

a.) What are the limitations of the ICP-MS?

b.) Which elements is it optimal for (generally)?

c.) Which elements will it not measure well?

A solution contains barium nitrate and lead (II) nitrate. What substance could be added to the solution to precipitate the lead (II) ions, but leave the barium ions in solution?

A) ammonium carbonate

B) no such substance exists

C) beryllium sulfate

D) silver nitrate

E) strontium bromide

Explain how the sulfur dioxide released in a coal-fired power plant in the U.S. can decrease the pH of a lake in Canada.

Describe how nitrogen oxides form HNO3 in the atmosphere.

For the diprotic weak acid H2A, Ka1 = 3.8 × 10-6 and Ka2 = 8.2 × 10-9. What is the pH of a 0.0750 M solution of H2A? What are the equilibrium concentrations of H2A and A2– in this solution?

1) pH

2) [H2A]

3) A^2-

Please explain all steps and equations, please...

A 0.07420 gram sample of methyl amine was mixed with 125.0 mL of a HCl solution. The back-titration of the unreacted acid required 5.35 mL of 0.1057 M KOH to reach the equivalence point. Determine the molarity of the acid.

Natural gas is primarily methane, CH₄, and is used to heat homes. A typical home is approximately 2000 ft² and the ceilings are 8 ft high. The following data may be helpful: The heat capacity of air is 1.01 J/g·K and the and the enthalpy of combustion of methane is -890.8 kJ/mol. Assume that the molecular weight of air is the same as nitrogen, its major component.

How many grams of methane are required to raise the temperature in the home from 39°F to 72°F?

How many grams of CO₂ does this reaction produce?

1. Structural steels have traditionally been used in shipbuilding; however, with

increasing fuel costs, it is desirable to find alternative lower weight materials.

Some of the key properties required for shipbuilding materials are high yield

strength, high corrosion resistance, and low cost. Discuss the benefits and

disadvantages of aluminum alloys as a replacement for structural steels in ships.