After 1.60 mol of NH3 gas is placed in a 1600-cm^3 box at 25 degrees C, the box is heated to 500 K. At this temperature, the ammonia is partially decomposed to N2 and H2, and a pressure measurement gives 4.85 MPa. Find the number of moles of each component present at 500 K.

Using the paper, “Multiparametric Atomic Force Microscopy Imaging of Biomolecular and Cellular Systems”, describe what is meant by “Multiparametric AFM”.  Describe the impact and advantages of this approach. (Acc. Chem. Res. 2017, 50, 924−931)

Compare and contrast scanning tunneling microscopy (STM) and atomic force microscopy (AFM)? List at least two advantages and two disadvantages for both methods. Please reference at least one source in your discussion.

To calculate the isoelectric point of amino acids having other ionizable functional groups, we must also take into account the

pK_a

of the additional functional group in the side chain.

Indicate which

pK_a

values must be used to calculate the pI of the following amino acids: [1] aspartic acid; [2] arginine; [3] lysine. Be sure to answer all parts.

What additives may be used to prevent acid catalyzed hydrolysis of drugs containing ester moieties in drug formulations?

A buffer solution is made by dissolving .17g of ammonia and 1.07g ammonium chloride in enough water to make 250mL of solution

Detemine molarity of ammonium chloride

Detemine ammonium concentration

Determin solution molarity relative to ammonia

Determine solution pH

1. Discuss the applicatoin of distillation as a separation and purificatoin technique. Are there limits due to sample size, initial purity and final purity desired?

2. Discuss the applicatoin of gas chromatogrpahy as a separations and identification technique. Are there limits due to purity, sample size, phase of sample?

At 200 K, the compression factor of oxygen varies with pressure as shown in the table below. Evaluate the fugacity of oxygen at this temperature and 124 atm.

1. (a) What is the Na⁺ concentration in each of the following solutions:

2.85 M sodium sulfate:

2.18 M sodium carbonate:

0.985 M sodium bicarbonate:

(b) What is the concentration of a lithium carbonate solution that is 0.395 M in Li⁺? M

2. A sample of 0.7160 g of an unknown compound containing barium ions (Ba²⁺) is dissolved in water and treated with an excess of Na₂SO₄. If the mass of the BaSO₄ precipitate formed is 0.6894 g, what is the percent by mass of Ba in the original unknown compound?

3. A 0.9080 g sample of a mixture of NaCl and KCl is dissolved in water, and the solution is then treated with an excess of AgNO₃ to yield 1.953 g of AgCl. Calculate the percent by mass of each compound in the mixture.

% mass NaCl

% mass KCl

4. The concentration of lead ions (Pb²⁺) in a sample of polluted water that also contains nitrate ions (NO₃⁻) is determined by adding solid sodium sulfate (Na₂SO₄) to exactly 500 mL of the water. Calculate the molar concentration of Pb²⁺ if 0.00260 g of Na₂SO₄ was needed for the complete precipitation of lead ions as PbSO₄.

5. Consider the reaction

H₂(g) + Cl₂(g) → 2HCl(g) Δ H = −184.6 kJ/mol

If 5.0 moles of H₂ reacts with 5.0 moles of Cl₂ to form HCl at 1.0 atm, what is Δ U for this reaction? Assume the reaction goes to completion and Δ V = 0 L.
(The conversion factor is 1 L atm = 101.3 J.)

a)During an experiment, a student mixed 14.5mL of a 0.500 M sodium fluoride solution with 15.6 mL of a 0.750 M hydrofluoric acid solution the measured pH was 3.24.Calculate the pKa.b)Calculate th pH of a solution prepared by mixing 20.5 mL of a 0.500 M sodium flouride solution with 32.5 mL of a 0.750 M hydrofluoric acid solution. Use pKa from question 1

Aluminum chloride is made from aluminum metal and chlorine gas, as shown:

2Al(s) + 3Cl2(g) ---> 2AlCl3(s)

When 10.0g of aluminum and 25.0g of chlorine are reacted, 18.6g of aluminum chloride is formed. Determine:

a) the limiting reactant

b) the theoretical yield in grams

c) the percent yield for this reaction

d) the excess reactant in grams

A cough medicine contains 0.40% (w/v) dextromethorphan, a cough suppressant, and

1.2% (w/v)

guaifenisin, an expectorant.

How many

milligrams of each drug would you obtain from

3.5 tsp

of cough syrup?

(1 tsp = 4.93 mL)

Consider the following balanced equation: 2N2H4(g)+N2O4(g)→3N2(g)+4H2O(g) Complete the following table showing the appropriate number of moles of reactants and products. If the number of moles of a reactant is provided, fill in the required amount of the other reactant, as well as the moles of each product formed. If the number of moles of a product is provided, fill in the required amount of each reactant to make that amount of product, as well as the amount of the other product that is made.

Balance following simple redox reaction Ca(s) + blank Fe+3(aq) blank + ca+2(aq) + Fe

12. Write the appropriate nuclear symbol for each of the following isotopes: (a) Z = 11, A = 23 (b) Z = 28, A = 64 (c) Z = 50, A = 115 (d) Z = 20, A = 42

20. Ethane and acetylene are two gaseous hydrocarbons. Chemical analysis show that one sample of ethane contains 2.65 g of carbon and 0.668 g of hydrogen, and one sample of acetylene contains 4.56 g of carbon and 0.382 g of hydrogen. Write reasonable empirical formulas for these compounds. Ethane: Acetylene:

22. The atomic masses of 35Cl (75.53%) and 37Cl (24.47%) are 34.968 amu and 36.956 amu, respectively. Calculate the average atomic mass of chlorine. The percentages in parentheses denote the relative abundances ________ amu 26. Consider the combustion of carbon monoxide (CO) in oxygen gas: 2CO(g) + O2(g) → 2CO2(g) Starting with 3.09 moles of CO, calculate the number of moles of CO2 produced if there is enough oxygen gas to react with all the CO

27. The fertilizer ammonium sulfate, (NH4)2SO4, is prepared by the reaction between ammonia (NH3) and sulfuric acid 2NH3(g) + H2SO4(aq) → (NH4)2SO4(aq) How many kilograms of NH3 are needed to produce 3.60 × 105 kg of (NH4)2SO4? Enter your answer in scientific notation.

28. Identify each of the following as a combination, decomposition, or combustion reaction: C2H4O2(l) + 2O2 → 2CO2(g) + 2H2(l) 2Na(s) + Cl2(g) → 2NaCl(s) 2NaH(s) → 2Na(s) + H2(g)

35. (a) What is the Na+ concentration in each of the following solutions: 3.05 M sodium sulfate: M 1.98 M sodium carbonate: M 0.185 M sodium bicarbonate: M (b) What is the concentration of a lithium carbonate solution that is 0.795 M in Li+? 37.A sample of 0.7960 g of an unknown compound containing barium ions (Ba2+) is dissolved in water and treated with an excess of Na2SO4. If the mass of the BaSO4 precipitate formed is 0.8916 g, what is the percent by mass of Ba in the original unknown compound?