a) Write the net ionic equations for any reaction that occurs when each of the following salts are dissolved in water (if no reaction occurs, write "NR"):
ammonium nitrate
potassium bromide
cesium formate
b) When does the cation of a salt react with water. Illustrate answer using KBr and NH4Br:
c) When does the anion of salt react with water. Illustrate answer using KBr and KF:
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You dissolve a compound with a molecular mass of 289.49 in a 10-mL volumetric flask. You remove a 1.00-mL aliquot, place it in a 25-mL volumetric flask and dilute it to the mark. The absorbance of this diluted solution at 341 nm was 0.444 in a 1.000-cm cuvet. The molar absorptivity for this compound at 341 nm is ε341 = 6117 M–1 cm–1.
(a) What is the concentration of the compound in the cuvet?
(b) What is the concentration of the compound in the 10-mL flask?
(c) How many milligrams of compound were used to make the 10-mL solution?
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Predict whether N2 is likely to have a relatively high
or low boiling point.
|
high |
|
|
low |
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Dalton's Law Of Partial Pressure show all calculations!!
a.) Earth's atmosphere consist of 78% N2 and 20% O2, and other gases. What is the partial pressure of N2 and O2 in torr, when atmospheric pressure is 1 atm?
b.) Ammonia is completely decomposed to nitrogen and hydrogen as in question 9b) At the end of the experiement the pressure of the gas mixture is 866 mmHg. Calculate the partial pressures of N2 and H2
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11)
What are the coefficients in front of
NO3-(aq) and Cu(s) when the
following redox equation is balanced in an acidic solution:
___ NO3-(aq) + ___ Cu(s) →
___ NO(g) + ___
Cu2+(aq)?
Select one:
A. 3, 6
B. 2, 6
C. 2, 3
D. 3, 4
12)
The values of ΔH°f for the three states of benzene are approximately -22 kcal/mol, -11 kcal/mol, and 20kcal/mol. Which is the value for solid benzene?
Select one:
A. -22 kcal/mol
B. 20 kcal/mol
C. -11 kcal/mol
D. cannot be determined without additional information
13)
Calculate the total quantity of heat required to convert 25.0 g of liquid CCl4(l) from 35.0°C to gaseous CCl4 76.8°C (the normal boiling point for CCl4)? The specific heat of CCl4(l) is 0.857J/gC its heat of fusion is 3.27kj/mol and its heat of vaporization is 29.82kJ/mol.
Select one:
A. 1.43 kJ
B. 6.28 kJ
C. 5.74 kJ
D. 0.896 kJ
18)
When heated, mercury(II) oxide decomposes into elemental mercury
and oxygen:
2 HgO(s) → 2 Hg(l) + O2(g)
ΔH° = 181.6 kJ ΔS° = 216.4 J/K
Estimate the temperature at which HgO should begin to decompose if
the partial pressure of O2(g) is constant at
1.00 atm.
Select one:
A. 840°C
B. -34.8°C
C. 34.8°C
D. 566°C
19)
When 50.0 mL of 0.400 M Ca(NO3)2 is added
to 50.0 mL of 0.800 M NaF, CaF2 precipitates, as shown
in the net ionic equation below. The initial temperature of both
solutions is 25.00°C. Assuming that the reaction goes to
completion, and that the resulting solution has a mass of 100.00 g
and a specific heat of calculate the final temperature of the
solution.
Ca2+(aq) + 2
F-(aq) → CaF2(s)
ΔH° = -11.5 kJ
Select one:
A. 24.45°C
B. 26.10°C
C. 26.65°C
D. 25.55°C
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Physical chemistry
. The osmotic of an aqueous solution at 351 K is 94 kPa and a density of 1,152 g/mL. Calculate the freezing point (in C) of the solution. The Kf for water is 1.86oC/m.
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How does pentobarbital, pancuronium bromide, and potassium chloride accomplish cessation of life?
Please include a source(s)!! It is a necessity! Thank you.
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If a temperature scale were bassed on the freezing point (5.5 degrees Celsius) and boiling point (80.1 degrees Celsius) of benzene, and the temperature difference between these two points was divided into 50 units called degrees X, what would be the freezing and boiling points of water in degrees X?
In: Chemistry
In addition to the molecular orbital treatment of H2, the ground state can be treated by the so-called valence bond (Heitler-London) approach, where individual covalent bonds are combined to form an antisymmetric wave function with spins up and down. Look up this approach and compare the results with the simple MO treatment in terms of bond energy (kJ/mol) and bond distance (pm).
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10Na + 2NaNo3 yields 6Na2O + N2
how many grams of sodium oxide will be made by combining 25.0 grams of sodium with 47.0 grams of sodium nitrate?
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Balance the given redox reaction.
NaClO3 + H2O + I2 --> HIO3 + NaCl
?please show all steps
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Devise a procedure for the separation and purification of the mixture containing 0.25g benzoic acid, 0.20g benzil, 0.05 p-dichlorobenzene.
Available reagents: 1M NaOH, 1M HCI, 1M NaHCO3, 6 M NaOH, 6 M HCI, saturated solution of NaCl, diethyl ether, 95% ethanol, methanol, isopropyl alcohol, acetone, hexane, toluene, ethyl acetate, anhydrous sodium sulfate.
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The Ka of acetic acid is 1.8 x 10^-5 at 25C.
a) What is the pH of a 0.5 M solution of acetic acid at 25C?
b)What is the pH of a solution made up of 20 mL of 0.5 M solution of acetic acid and 10 mL of 0.5 M sodium acetate?
c) If 10 mL of 0.1 M NaOH is added to the solution in part b, what is the final pH?
d) What is the pH of a solution containing equal concentrations of acetic acid and sodium acetate?
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1. Would a 50:50 solution of R and S enantiomers of the same compound have any effect on plane polarized light shining through it? Why or why not?
2. Based on your answer to the last question, how could you determine the enantiopurity of a given concentration of a sample if you know its specific rotation [α] using a polarimeter?
3. Give an example of a drug which can be sold as a racemic (R and S) mixture without any harmful effects.
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Phosphoric acid is a triprotic acid (Ka1=6.9x10-8, Ka2 = 6.2x10-8, and Ka3=4.8x10-13). To find the pH of a buffer composed of H2PO4- (aq) and HPO42-(aq), which pka value would you use in the Henderson-Hasselbalch equation? Calculate the pH of a buffer solution obtained by dissolving 22.0 g of KH2PO4 and 32.0 g of Na2HPO4 in water and then diluting to 1.00 L
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