A sample of gas contains 0.1600 mol of CH4(g) and 0.1600 mol of H2O(g) and occupies a volume of 12.1 L. The following reaction takes place: CH4(g) + H2O(g)-----3H2(g) + CO(g) Calculate the volume of the sample after the reaction takes place, assuming that the temperature and the pressure remain constant. ____(?)Liters

1a.Consider a neutral carbon atom that has six electrons orbiting the nucleus. Suppose that five of the electrons are in their lowest states, but the sixth is in a very high state. Why might the energy levels for the outermost electron be similar to those for the single electron in hydrogen. (Hint: think of what is exerting an electrical force on the outermost electron)

1b.

- Arrange the standard spectral sequence - O, B, A, F, G, K, M - in order of decreasing Ha strength

1c. a) How many times more abundant is Helium than sodium

b) In general what can be said of the abundances of elements heavier than iron.

c) Calculate the ratio of iron to Uranium, iron to carbon and iron to iodine.

d) Do your values in C support what you said in B. Yes or no. Why?

1d. What do expect the formula for the combination of Potassium (K) and sulfur (S) to be ? Also the formula for Lithium(Li) to Fluoride(F)?

A mixture of carbon dioxide and nitrogen gases, at a total pressure of 889 mm Hg, contains 7.17 grams of carbon dioxide and 5.38 grams of nitrogen. What is the partial pressure of each gas in the mixture?

PCO2 =___(?)___ mm Hg

PN2 = __(?)__ mmHg

What is the pH of a solution obtained by adding 50.0 mL of 0.100 M NaOH (aq) to 60.0 mL of 0.100 M HCl (aq)?

Select one:

a. 11.96

b. 2.04

c. 3.11

d. 7.00

QUESTION 2

What is the pH of a solution prepared by dissolving 5.86 grams of propanoic acid, CH₃CH₂COOH (l), and 1.37 grams of NaOH (s) in enough water to make exactly 250.0 mL of solution. pK_a = 4.87 for propanoic acid?

Select one:

a. 4.58

b. 4.87

c. 4.75

d. 4.62

Lead is a toxic metal that affects the central nervous system. A Pb-contaminated water sample contains 0.0010 % Pb by mass

How much of the water (in mL) contains 145 mg of Pb? (Assume a density of 1.0 g/mL.) Express your answer using two significant figures.

Calculate the solubility (in grams per 1.00×102mL of solution) of magnesium hydroxide in a solution buffered at pH = 12. Express your answer using two significant figures. I got S1 = 1.2×10^-8 which is correct but for this part i did not get it "How does this compare to the solubility of Mg(OH)2 in pure water? "Express your answer using two significant figures. please solve it i could not get the answer.

Rank each of the following compounds in decreasing order of reactivity towards Friedel-Crafts alkylation. Most reactive = 1; if a compound will not react, rank it as "non" rather than assigning a numerical value. Compound A: fluorobenzene Compound B: phenol Compound C: benzaldehyde Compound D: acetophenone

Determine the pH at the equivalence (stoichiometric) point in the titration of 41 mL of 0.25 M C6H5COOH(aq) with 0.27 M NaOH(aq). The Ka of benzoic acid is 6.5 x 10-5.

What volume, in liters, of 1.04 M KOH solution should be added to a 0.107 L solution containing 9.26 g of glutamic acid hydrochloride (Glu, FW = 183.59 g/mol; pKa1 = 2.23, pKa2 = 4.42, pKa3 = 9.95) to get to pH 10.37?

1) In H NMR spectroscopy, why is the peak for a vinyl proton, C=C-H, shifted downfield relative to that of an alkane proton, C(sp³)-H? Be sure to use the following terms in your answer: pi-electrons, induced magnetic field, and resonance.

2)  In H NMR spectroscopy, why is the peak for a -CH₂F group shifted downfield relative to that for a -CH₂Br group? Be sure to use the following terms in your answer: electronegative, deshielded, magnetic field, and frequency.

Table salt, NaCl(s), and sugar, C12H22O11(s), are accidentally mixed. A 3.50-g sample is burned, and 2.10 g of CO2(g) is produced. What was the mass percentage of the table salt in the mixture?

Calculate the expected change in temperature for 25.00 mL of 0.500 M HCl reacting with 25.00 mL of 0.500 M NaOH. The heat Capacity of the Calorimeter is 15.6 J C -1 and the molar Enthalpy of Neutralization is -55.83 kJ mole . (Remember to use -1 dimensional analysis)

Agree or disagree with the following statements. Support your answer with chemical reasoning, calculations, analogies, examples, etc.

a. Since sugar is soluble in water, the lattice energy must be greater than the hydrogen bonds holding water together.

b. The addition of salt to water raises the boiling point, lowers the freezing point, lowers the vapor pressure, and makes the water boil faster.

c. The three factors that determine how fast a chemical reaction occurs are concentration, half-life, and enthalpy

a. Write the chemical reactions whose equilibrium constants are Kb and Ka for imidazole and imidazole hydrochloride, respectively.

b. Calculate the pH of a solution prepared by mixing 1.00 g of imidazole with 1.00 g of imidazole hydrochloride and diluting to 100.0 mL. A: 7.27

c. Calculate the pH of the solution if 2.30 mL of 1.07 M HClO4 are added.

I just ned help with c please!

For the reactions shown below, we added 3.75 mL of 0.0420 M Na₂S to a test tube containing one of the two cations (Cu²⁺ or Cd²⁺) and recovered 0.0228 g of precipitate.

Cu(NO₃)₂(aq) + Na₂S(aq) → CuS(s) + 2 NaNO₃(aq)
Cd(NO₃)₂(aq) + Na₂S(aq) → CdS(s) + 2 NaNO₃(aq)

How much precipitate in moles would be recovered theoretically if the ion was Cu²⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in moles would be recovered theoretically if the ion was Cd²⁺? (Enter an unrounded value. Use at least one more digit than given.)
mol

How much precipitate in grams would be recovered theoretically if the ion was Cu²⁺?


How much precipitate in grams would be recovered theoretically if the ion was Cd²⁺?


Based on the precipitate amount recovered, which of the two ions was in the unknown?