what is the relationship between volatility and the vapor pressure of a solvent
In: Chemistry
We’re going to titrate formic acid with the strong base, NaOH. There is initially 100. mL of 0.50 M formic acid and the concentration of NaOH is 1.0 M.
A. What is the initial pH of the formic acid solution?
B. What is the percent ionization under initial conditions?
C. After the addition of 10 mL of NaOH, what is the pH?
D. After the addition of 25 mL of NaOH, what is the pH? Think about where in the titration this brings you.
E. What volume of NaOH is required to reach the equivalence point?
F. What is the pH at the equivalence point?
G. What is the pOH at the equivalence point?
H. If, instead of NaOH being added, 0.05 moles of HCl is added by bubbling the gas through the solution. Assume that the volume has not changed. What is the percent dissociation of formic acid?
Sorry! i know its alot
In: Chemistry
Important equations for making up solutions Weight of solute (g) = formula weight of solute (g/mole) x molarity (mol/l) x final volume (L) C1V1 = C2V2 |
How to make solutions
Choose the correct formula from above. Please show all the steps and be sure to clearly show what values are being using relating to the formula.
Parallel Dilution Technique
Concentration of KMnO4 |
Volume of 0.01M KMnO4 Solution needed |
Volume of dH2O needed |
|
1 |
1.0 mM KMnO4 |
||
2 |
0.6 mM KMnO4 |
||
3 |
0.4 mM KMnO4 |
||
4 |
0.2 mM KMnO4 |
||
5 |
100 µM KMnO4 |
||
6 |
40 µM KMnO4 |
||
7 |
20 µM KMnO4 |
In: Chemistry
In: Chemistry
1) Each molecule of testosterone contains 19 atoms of carbon (plus other atom). The mass percent of carbon in testosterone is 79.12%. What is the molar mass of testosterone?
2) A substance contains 23.0g of sodium, 27.0 g aluminum and 114.0 g fluorine. How many grams of sodium are there in a 159 g sample of the substance?
In: Chemistry
Industrial chemists make hydrofluoric acid (which is used in aluminum and uranium processing, to etch glass, and to make CFCs) from the reactions of aqueous calcium fluoride and aqueous sulfuric acid. Write the complete equation for this reaction. (Use the lowest possible coefficients. Include states-of-matter in your answer.)
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In: Chemistry
Constants
Heat of fusion (?Hfus) is used for calculations involving a phase change between solid and liquid, with no temperature change. For H2O, ?Hfus=6.02 kJ/mol.
Specific heat capacity (C) is used for calculations that involve a temperature change, but no phase change. For liquid water, C=4.184 J/(g??C).
Heat of vaporization (?Hvap) is used for calculations involving a phase change between liquid and gas, with no temperature change. For H2O, ?Hvap=40.7 kJ/mol.
Part B
How much heat is required to raise the temperature of 92.0g of water from its melting point to its boiling point?
Express your answer numerically in kilojoules.
In: Chemistry
A student collected the following data as part of the Determination of KClOx:
Temperature: 23.0 oC
Atmospheric Pressure: 749.3 torr
PH2O: 21.454 torr
Volume of O2: 89 mL
Mass of KClOx: 0.372 g
a. Determine the moles of O2 collected and the moles of monoatomic oxygen, O.
b. Determine the mass of O2 and of KCl at the end of the reaction.
c. Determine the mole ratio of O to KCl and provide the formula for the unknown
In: Chemistry
When a pink aqueous solution of potassium permanganate, faintly acidified with dilute sulfuric acid was treated with 10% aq. hydrogen peroxide, the reaction took place with the evolution of gas bubbles, and the pink solution was turned colorless. Further chemical analysis revealed that the evolved gas was oxygen, and the resulting solution contains potassium sulfate and manganese (II) sulfate; water was also formed during the same reaction. Please answer the followings: 1) Write down the proper chemical equation for this reaction. 2) Balance the chemical equation. 3) Define the type/types of the reaction, and offer an explanation for the color change. 4) Write down the ions (and define types) present in the solution before & after the reaction. 5) If initially 5.65 g of potassium permanganate was taken for the reaction, calculate the total number of moles of manganese (II) sulfate present in the solution after the completion of the reaction
In: Chemistry
What is the equivalence point pH for the titration of 25ml 0.80M diethyleneamine (kb = 5.9x10-4) titrated by 0.60M strong acid? A. 3.74 B. 5.62 C.6.55 D. 8.62
In: Chemistry
Complete the following table:
Ppm Grams Air Volume (l) Mol. Wt. (g)
_______ 0.02542 75 339
2 0.00228 300 _____
1000 7.164 _____ 146
0.002 _____ 2650 254
In: Chemistry
Complete and balance the following equations, and identify the oxidizing and reducing agents. (Use the lowest possible coefficients. Include states-of-matter (s), (l), (g), (aq) similar to the given reaction.)
a.) MnO4-(aq) + CH3OH(aq) ? Mn2+(aq) + HCO2H(aq) (acidic solution)
b.) H2O2(aq) + Cl2O7(aq) ? ClO2-(aq) + O2(g) (basic solution)
c.) Cr2O72-(aq) + I-(aq) ? Cr3+(aq) + IO3-(aq) (acidic solution)
d.) As(s) + ClO3-(aq) ? H3AsO3(aq) + HClO(aq) (acidic solution)
In: Chemistry
A buffer solution is composed of 1.905 g of KH2PO4 and 5.181 g of Na2HPO4. ( Ka for dihydrogen phosphate ion is 6.2x10^-8 .)
a. What is the pH of the buffer solution?
pH =
b. What mass of KH2PO4 must be added to decrease the buffer solution pH by 0.10 unit from the value calculated in part a?
Mass =
(Volume not given)
In: Chemistry
8.03 x 10^23 moleucles of oxygen react with excess nitrogen. what is the maximum number of grams of dinitrogen tetroxide that can be produced?
42 grams of cyclohexane burns in excess air to form carbon dioxide and water. How many grams of carbon dioxide and of water vapor are produced?
In: Chemistry
Suppose a particular mechanism has the following equilibria:
Ni(CO)4(g) ⇌ Ni(s) + 4 CO(g) K1 = 8.77 ΔH1 = 190 kJ
MnO(s) + CO(g) ⇌ Mn(s) + CO2(g) K2 = 490 ΔH2 = 349 kJ
Mn(s) + H2O(g) ⇌ MnO(s) + H2(g) K3 = 0.0149 ΔH3 = -346 kJ
Determine the values of the equilibrium constant and enthalpy change for the net equation:
Ni(CO)4(g) + 4 H2O(g) ⇌ Ni(s) + 4 CO2(g) + 4H2(g) Kc = ? ΔH = ?
(You’ll want to review the rules for manipulating the stoichiometry of an equilibrium reaction and its equilibrium constant in section 14.3 of the textbook. It is different than using Hess’s Law to find the net enthalpy change.)
3 species do not appear in the net question. Which are they? Classify each as an intermediate or a catalyst. How do you know the difference?
In: Chemistry