Determine the equation for the best straight line for the calibration curve from the following set of absorbance/concentration (mg/100 mL) data: 0.96/0.0, 0.83/10, 0.66/20, 0.49/30, 0.36/40, 0, 19/50, 0.08/60.
What method did you use to obtain the equation for the best straight line, what is the value of Ao, and what are the numerical value and units of k?
In: Chemistry
What is the [OH-] of a 1x10-3 M solution of NH4Cl?
In: Chemistry
A chemistry student needs to standardize a fresh solution of sodium hydroxide. She carefully weights out 305.mg of oxalic acid(H2C2O4), a diprotic acid that can be purchased inexpensively in high purity, and dissolves it in 250.mL of distilled water. The student then titrates the oxalic acid solution with her sodium hydroxide solution. When the titration reaches the equivalence point, the student finds she has used 69.4mL of sodium hydroxide solution. Calculate the molarity of the student's sodium hydroxide solution. Be sure your answer has the correct number of significant digits.
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A student creates a buffer mixing 50. mL of 1.0 M Acetic Acid with 25 mL of 1.0 M Sodium Hydroxide. The buffer is then mixed with 10. mL of 2.0 M hydrobromic acid. What is the pH of the final solution?
The Ka of acetic acid is 1.8 x 10-5
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Given the thermodynamic data in the table below, calculate the equilibrium constant (at 298 K) for the reaction:
2SO2 (g) + O2 (g) à 2SO3 (g)
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Explain the energy changes at the molecular level when
liquid acetone is conferred to vapor at it's boiling
point
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When either cis- or trans- 2 bromocyclohexanol is reacted with HBr, only the trans- 1,2- dibromocyclohexane is formed. Explain.
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Consider three gas connected gas containers as shown in the figure below.
Consider three gas connected gas containers as shown in the figure below.
CO2 (g) P = 2.13, V = 1.50L
H2(g) P = 0.861 atm, V = 1.00 L
Ar (g) p = 1.15atm, V = 2.00L
T = 298K
Assume, that you open the two stopcock so that the gases can flow freely.
Calculate the change of the chemical potential of the entire system due to mixing the gases.
Using the change of the chemical potential of gases show that the mixing of three gases is spontaneous
Determine the value of DmixH .
mix = ______________________
mixH = _____________________
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The rate of a certain reaction was studied at various temperatures. The table shows temperature (T) and rate constant (k) data collected during the experiments. Plot the data to answer the questions.
What is the value of the activation energy, Ea , for this reaction?
| T (K) | k (s−1) |
|---|---|
| 400 | 0.000108 |
| 420 | 0.000626 |
| 440 | 0.00310 |
| 460 | 0.0134 |
| 480 | 0.0511 |
| 500 | 0.175 |
| 520 | 0.547 |
| 540 | 1.57 |
| 560 | 4.18 |
| 580 | 10.4 |
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The mass of a lethal gas (HCN) is measured ot be 5.50 lbs. If this gas is incinerated in a high temperature oven with a volume of 750 cubic feet determine the temperature of the oven. Assume that the gas is at the same pressure as the atmosphere which is 755 Torr and the temperature of the gas is the same as the oven. (1 Cubic Ft = 28.3168466 Liters) (454 g= 1 lbs)
A) 2109K
B) 2778K
C) 3021K
D) 2505K
I got 2781K so my answers is off, im not sure what i did
wrong
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Following dilution of a concentrated solution, the absorbance is determined to be 3.935 on our BioTek Plate Reader. What, if any, changes should be made to this experiment?
a The sample should be diluted at least two fold
b The sample should be concentrated 2 fold
c The sample should be diluted 100 fold
d The sample should be put into a different microplate.
e There is nothing wrong with this analysis and the 3.935 should be recorded.
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List a solution that you have contact with. Choose one that has not been discussed by a classmate. Give the composition of the solution; specify the units used to express the concentration. What is the solute? What is the solvent? Tell what the solution is used for.
How about the solution for dish soap.
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A mixture of propane and butane is burned with air. Partial analysis of the stack gas produces the following dry-basis volume percentages: 0.0527% C3H8, 0.0527% C4H10, 1.48% CO, and 7.12% CO2. The stack gas is at an absolute pressure of 780 mmHg and the dew point of the gas is 46.5 ˚C. Calculate the molar composition of the fuel.
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compare these different methods for determining the concentration of copper(II): titration, quantitative precipitation, and spectroscopy and discuss the applicability (under what conditions would each be preferable) of each method.
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Ammonium Nitrate+Potassium sulfide
a.Write the balance equation
b.Total ionic equation
c .Net equation
In: Chemistry