Gold forms a substitutional solid solution with silver. Compute the number of gold atoms per cubic centimeter for a silver-gold alloy that contains 10 wt% Au and 90 wt% Ag. The densities of pure gold and silver are 19.32 and 10.49 g/cm3, respectively.
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how would you convert potassium oleate soap to the corresponding fatty acid?
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1. A certain first-order reaction (A→products) has a rate constant of 1.00×10−2 s−1 at 45 ∘C. How many minutes does it take for the concentration of the reactant, [A], to drop to 6.25% of the original concentration?
2. A certain second-order reaction (B→products) has a rate constant of 1.15×10−3M−1⋅s−1 at 27 ∘C and an initial half-life of 200 s . What is the concentration of the reactant B after one half-life?
please show work
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Compute the approximate density of acetylene, C2H2, at 25 degrees C and 0.98 atm.
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So I went through a lab experiment last week, basically, We have a mixture and we remove iron with a magnet, we than seperate naphthalene by sublimation (by heating a flask). Than we have urea which is the only component that can dissolve in water which is obtained by crystallization after seperation from the polypropylene which floats on the water and the sand which sinks.
1) Describe the prinicpal diffuclties you encountered in obtaining a clean seperation and in collecting the seperated components without loss.
I really forgot the diffuclties I ecountered, anyone got an idea?
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A volume of 12.95 mL of 0.1080 M NaOH solution was used to titrate a 0.596 g sample of unknown containing K2HPO4.
a. What is the molecular mass of K2HPO4? (report answers to 4 or 5 significant figures)
b. What is the percent by mass of K2HPO4 in the unknown?
c. In this problem what mass of sample in grams would be needed to deliver about 22.00 mL in the next trial?
d. In the second trial above, exactly 0.996 g was transferred into a flask to be titrated. If the initial buret reading is 0.10 mL, predict what the final buret reading be.
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Working on an electrochemistry lab and I need to write the following net ionic equations based on the half reactions
Mg + AlCl3; Al + Pb(NO3)2; AgNO3 + Pb; Cu + MgSO4
I am aware of the half reactions for each of the solids, which I will include, but I'm confused about writing the half reactions for the compounds
Mg(aq) + 2e- --> Mg(s)
Al(aq) + 3e- --> Al(s)
Cu2+ (aq) + e- --> Cu+ (aq)
Pb2+ (aq) + 2e- --> Pb(s)
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PVA (Poly(vinyl alcohol))
1) Show that the average strand of PVA (MW 78,000) contains approximately 1800 monomer units.
2) Calculate the approximate length of PVA assuming that each monomer unit contributes two carbon atom diameters to the length (1 carbon atom diameter = 154 pm).
3) Show that 1.00 L of 4% (40g/L) PVA contains approximately 3 x 10^20 PVA strands.
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When 780g of benzene (molar mass = 78g/mol) reacts with 750ml of conc. HNO3 (16M) and 750ml of H2SO4 (18M), 1000g of nitrobenzene (molar mass =123g/mol) and 250g of an unknown compound with a high boiling point are obtained. a. Identify the limiting reagent
b. Calculate the percent yield of nitrobenzene
c. Give the name of the most probable side product with the high melting point
d. Explain with the aid of a mechanism the role of H2S04 in the reaction
e. Supposing the crystalline compound 250g has the formula C6H4N2O4, calculate the yield of the side product.
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How many joules of energy must be removed from 192 g of water at 23.6 C to form ice at 0 C? Significant digits is set to 3
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a.Normalize the wavefunction Ψ(x) = 1 in a space of 0 ≤ x ≤ ℓ
b. Find the probability of finding the particle in the subspace [0,ℓ/2 ]
c. Find the most-likely position of the particle in entire space
d. Find the most-likely position of the particle in the subspace [0,ℓ/3 ]
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Determine the rate law and the value of k for the following
reaction using the data provided.
2 NO(g) + O2(g) ? 2 NO2(g)
| [NO]i (M) | [O2]i (M) | Initial Rate (M-1s-1) |
| 0.030 | 0.0055 | 8.55 x 10-3 |
| 0.030 | 0.0110 | 1.71 x 10-2 |
| 0.060 | 0.0055 | 3.42 x 10-2 |
| Rate = 57 M-1s-1[NO][O2] | |
| Rate = 3.1 |
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The equilibrium constant, K, for the reaction below is 57.0 at 700K
Hydrogen gas plus iodine gas yields hydrogen iodide gas.
Write the balanced equation for the reaction. If 1.00 mol of hydrogen gas is allowed to react with 1.00 moles of iodine gas in a 10.0 Liter container, what are the concentrations of each gas at equilibrium?
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Give an equation or series of equations that can be used to determine the buried nonpolar surface area resulting from the formation of a macromolecular complex.
Your equation(s) should heat capacity change due to the hydrophobic effect.
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Low concentrations of methylmercury near the detection limit gave the dimensionless instrument readings: 208.1 , 176.5 , 165.1 , 177.1 , 222.1 , 162.9 , 225.9 , 204.5 , 137.5 , and 208.3 . Ten blanks had a mean reading of 41.9 . The slope of the calibration curve is 1.45 × 10 9 M − 1 . Estimate the signal and concentration detection limits and the lower limit of quantitation for methylmercury.
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