Explain how the solid phase extraction catridges separates the colorant (a potential interference) from the analytes.

Most of our discussion of transition metals has focused around them becoming positively charged ions. However, many of the transition metals will also become negatively charged ions. Using what you have learned from quantum mechanics and about electron configurations, predict which transition metals are most likely to form anions with a charge of -1 and explain the prediction.

In a titration of a 100.0mL 1.00M NH₃ solution with 1.00M HCl, what is the pH of the solution after the addition of 127 mL of HCl? K_b = 1.8 x 10^-5 for NH₃

Consider the titration of a 26.0-mL sample of 0.180 M CH3NH2 with 0.155 M HBr. (The value of Kb for CH3NH2 is 4.4×10−4.)

Determine the pH at 4.0 mL of added acid

Determine the pH at one-half of the equivalence point.

Determine the pH after adding 6.0 mL of acid beyond the equivalence point.

19.36:

Part A

Ca-40 (atomic mass = 39.96259 amu)

Express your answer using five decimal places.

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Part B

Express your answer using four significant figures.

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Part C

V-51 (atomic mass = 50.94396 amu)

Express your answer using five decimal places.

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Part D

Express your answer using four significant figures.

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Part E

Ag-107 (atomic mass = 106.905092 amu)

Express your answer using five decimal places.

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Part F

Express your answer using four significant figures.

Chlorophyll a and chlorophyll b are very closely related structures and you were not able to separate them from each other in this lab by column chromatography. For each of the following variables indicate what specific change, if any, could be made to the procedure to help you separate these compounds during your column chromatography.

Compare the advantages and limitations of column chromatography with those of thin-layer and gas chromatography. Discuss all 3 chromatography methods. When you would use them and in which case is each useful and not useful?

The anthocyanin in hydrangeas can be isolated and used as an environmentally friendly pH indicator for titrations. At the end of a titration reaction of a strong acid with a strong base, you have a neutral solution. What color do you expect anthocyanin to be at the end of a titration? Describe a lab experiment to support your prediction.

A 3.87 gram sample of ascorbic acid (Vitamin C) yield 5.80 grams of CO₂ and 1.58 grams of H₂O on combustion. What is the empirical formula of this compound? (This compound contains only C, H, and O.)

In an ideal solution of A and B, 2.75 mol are in the liquid phase and 4.255 mol are in the gaseous phase. The overall composition of the system is Z_A = 0.420, and x_A = 0.310. Calculate y_A.

1)When one atom transfers one or more valence electrons to another atom, a(n) ___ is formed.

A.Covalent Bond

B.Ionic Bond

C.Metallic Bond

D.All of the above

2)Typically, when two atoms form a chemical bond, the expected result is that the electrons

A.Will be in the excited state

B.Will be completely removed from both atoms

C.Will compete a noble gas configuration for both atoms

D.None of the above

3)Which of the statements about ionic solids is FALSE?

A.Ionic solids conduct electricity when dissolved in water.

B.Ionic solids are good conductors of electricity.

C.Ionic solids form crystals

D.Ionic solids can be formed by reacting an alkali metal with a halogen.

4)The balanced net ionic equation for the reaction between acetic acid and sodium hydroxide is:

A.H⁺(aq) + OH^-(aq) = H₂O(l)

B.HC₂H₃O₂(aq) + OH^-(aq) = C₂H₃O₂^-(aq) + H₂O(l)

C.H⁺(aq) + C₂H₃O₂^-(aq) + OH^-(aq) = C₂H₃O₂^-(aq) + H₂O(l)

D.H⁺(aq) + C₂H₃O₂^-(aq) + OH^-(aq) = C₂H₃O₂^-(aq) + H⁺(aq) + OH^-(a)

What is the initial pH, at half way and after 12.5 mL of NaOH 0.3235 M is used to titrate 65.00 mL of 0.1237 M HAc?    Ka=1.75 x 10^-5

For calcite dissolution experiment, when you increase ionic strength from 0 (infinite diluted) to 0.1 m, how much does the solubility increase？

At 650 K, the reaction MgCO3(s)?MgO(s)+CO2(g) has Kp=0.026. A 12.5L container at 650 K has 1.0 g of MgO(s) and CO2 at P = 0.0260 atm. The container is then compressed to a volume of 0.500L . Find the Mass of MgCO₃ that is formed

A titration is a procedure for determining the concentration of a solution by allowing it to react with another solution of known concentration (called a standard solution). Acid-base reactions and oxidation-reduction reactions are used in titrations. For example, to find the concentration of an HCl solution (an acid), a standard solution of NaOH (a base) is added to a measured volume of HCl from a calibrated tube called a buret. An indicator is also present and it will change color when all the acid has reacted. Using the concentration of the standard solution and the volume dispensed, we can calculate molarity of the HCl solution.

Part A

A volume of 70.0 mL of aqueous potassium hydroxide (KOH) was titrated against a standard solution of sulfuric acid (H2SO4). What was the molarity of the KOH solution if 17.7 mL of 1.50 M H2SO4 was needed? The equation is

2KOH(aq)+H2SO4(aq)→K2SO4(aq)+2H2O(l)

Express your answer with the appropriate units.

Redox titrations are used to determine the amounts of oxidizing and reducing agents in solution. For example, a solution of hydrogen peroxide, H2O2, can be titrated against a solution of potassium permanganate, KMnO4. The following equation represents the reaction:

2KMnO4(aq)+H2O2(aq)+3H2SO4(aq)→3O2(g)+2MnSO4(aq)+K2SO4(aq)+4H2O(l)

A certain amount of hydrogen peroxide was dissolved in 100. mL of water and then titrated with 1.68 M KMnO4. What mass of H2O2 was dissolved if the titration required 18.3 mL of the KMnO4 solution?

Express your answer with the appropriate units.