As a chemist for an agricultural products company, you have just developed a new herbicide,"Herbigon," that you think has the potential to kill weeds effectively. A sparingly soluble salt, Herbigon is dissolved in 1 M acetic acid for technical reasons having to do with its production. You have determined that the solubility product Ksp of Herbigon is 8.00×10−6.
Although the formula of this new chemical is a trade secret, it can be revealed that the formula for Herbigon is X-acetate (XCH3COO, where "X" represents the top-secret cation of the salt). It is this cation that kills weeds. Since it is critical to have Herbigon dissolved (it won't kill weeds as a suspension), you are working on adjusting the pH so Herbigon will be soluble at the concentration needed to kill weeds. What pH must the solution have to yield a solution in which the concentration of X+ is 4.50×10−3M ? The pKa of acetic acid is 4.76.
In: Chemistry
Which of the following is an example of the law of multiple proportions?
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two different samples of table salt are found to have the same ratio sodium to chlorine |
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carbon dioxide always has the same mass ratio |
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a sample of chlorine is found to contain three times as mush 35Cl as 37Cl. |
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two different compounds formed from nitrogen and oxygen have the following mass ratio: 1g N: 2.28 g O and 2g N : 2.28 g O |
In: Chemistry
When 28 g of calcium chloride was dissolved in 100g water in a coffee-cup calorimeter, the temperature rose from 25* Celcius to 41.3. What is the enthalpy change for this process? Assume the solution is equal to the specific heat of water.
In: Chemistry
Determine the integrated form of the third-order rate law of the form:
-d[A]/dt = k[A]^3.
Starting from a 0.5 M initial concentration of A, and a rate constant of 0.1 M^-2 * s^-1, how much time would be required before reaching a 0.3M concentration of A?
Answer Options
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78.2 s |
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35.6 s |
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22.3 s |
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13.7 s |
In: Chemistry
How does increasing the temperature of a liquid affect the rate of vaporization?
Increasing the temperature has no effect on the rate of vaporization.
The rate of vaporization decreases.
The rate of vaporization increases.
How does increasing the surface area of a liquid affect the rate of vaporization?
The rate of vaporization increases.
The rate of vaporization decreases.
Increasing the surface area of a liquid has no effect on the rate of vaporization.
How does the rate of vaporization for two liquids with differing intermolecular forces compare assuming all other variables are constant?
Intermolecular forces have no effect on the rate of vaporization. The two liquids will have the same rate of vaporization assuming all other variables are constant.
The liquid with the stronger intermolecular forces has a greater rate of vaporization than the liquid with the weaker intermolecular forces.
The liquid with the weaker intermolecular forces has a greater rate of vaporization than the liquid with the stronger intermolecular forces.
In: Chemistry
In: Chemistry
Additional aspects of aqueous solution:
4. In a 50.0mL titration of a strong acid (HCl) with a strong base (NaOH) calculate the pH when the following volumes of a 0.100M NaOH solution are added:
a.45.0mL
b.51.0mL
In: Chemistry
25.0 mL of a 4.21 M HCl solution at 25.2°C and 50.0 mL of a 2.50 M NaOH solution at 25.2°C are reacted together to give a final temperature of 44.1°C. The specific heat of the solution is 3.88 J/g°C and it weighs 76.6 grams. From this information, determine:
a. the limiting reactant for this reaction
b. the heat produced by the reaction (q) in units of Joules.
c. the enthalpy of the reaction (∆H) in units of kJ/mole.
In: Chemistry
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mL HCl added |
pH |
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0.00 |
11.86 |
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25.0 |
10.71 |
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50.0 |
6.09 |
A titration of 25.0 mL of 0.100 M triethylamine ((CH3CH2)3N) was performed with 0.0500 M HCl. Given the following data calculate the pKa for triethylammonium ion.
In: Chemistry
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In: Chemistry
The Clausius-Clapeyron equation and the Antoine equation. The vapor pressure of a liquid can be written in the empirical form known as the Antoine equation, ln (p / p ◦ ) = A1 − (A2 /(T + A3)) where A1, A2, and A3 are empirical constants determined from measurements, and T is the temperature in Kelvin.
(a) Starting with this equation, derive an equation for the enthalpy of vaporization as a function of temperature.
(b) For ethanol (l), A1 = 23.58, A2 = 3.67 × 103 , A3 = −46.702, and p ◦ = 1 Pa. Given that the standard pressure is 1 bar = 1.01325 × 105 Pa, what is the standard boiling temperature?
(c) Calculate ∆h at 298 K and at the standard boiling temperature.
In: Chemistry
The boiling point elevation constant for water is 0.51 degrees C/m. What is the boiling point of a solution made by dissolving 21.6g of a non-ionizing solute with a molar mass of 103.5 g/mol in 187g of water?
In: Chemistry
Motion of an election in a hydrogen atom corresponds to the potential energy U(r) = − e^2/(4πε0r) ,
4πε0 r which comes from the Coulomb attraction between the electron and the proton. Using the uncertainty
relation between the momentum of the electron, and its position, estimate the size of the hydrogen atom.
In: Chemistry
Consider the reaction:
SO2Cl2(g)⇌SO2(g)+Cl2(g)
Kp=2.91×103 at 298 K
In a reaction at equilibrium, the partial pressure of SO2 is 0.135
atm and that of Cl2 is 0.342 atm .
Part A
What is the partial pressure of SO2Cl2 in this mixture?
In: Chemistry
The Li2+ ion is hydrogenic and has a Lyman series at 740747 cm-1, 877924 cm-1, 925933 cm-1 and beyond. Show that the energy levels are of the form –hcR/n2 and find the value of R for this ion. Go on to predict the wavenumbers of the two longest wavelength transitions of the Balmer series of the ion and find the ionization energy of the ion.
In: Chemistry