How many grams of dipotassium succinate trihydrate (K2C4H4O4�3H2O, MW = 248.32 g/mol) must be added to 540.0 mL of a 0.0306 M succinic acid solution to produce a pH of 5.969? Succinic acid has pKa values of 4.207 (pKa1) and 5.636 (pKa2).

The experiment is Determination of Acetic Acid in Vinegar. Please answer as many questions as you can.

What are primary and secondary standards? Give examples.

What is KHP and why was it used in this lab?

How is acetic acid formed in vinegar solution?

Why are pH indicators strongly colored even in solid state?

Why/how do pH indicators change colors in acid-base solutions?

Molar mass of acetic acid is often calculated or experimentally measured as 120 g/mol. Why?

Suggest another analytical method to determine the end point of an acid-base titration.

pH indicators are often weak acids or bases. Would adding indicators interfere with the determination of the endpoint for desired acid-base titration?

If a solution of NaOH is prepared and standardized today and left on the bench for a week, would you expect the pH of the solution change? Why? Ignore solvent (water) evaporation.

You had titrated unknown vinegar solution in flask against standard NaOH from burette using phenolphthalein indicator. If you had titrated standard NaOH solution in flask against unknown vinegar solution in burette using the same indicator, would it be easier or more difficult? Why?

H2A is a diprotic acid with Ka1+1.43 x 10^-3 and Ka2=2.01 x 10^-6. Consider the titration of 50.0mL of 0.300 M Na2A with 0.150 M HCL. Find the pH at the following volumes of HCl (a) 0.00ml (b) 50.0ml (c) 100.0ml (d) 175.0ml (e) 200.0ml (f)230.00ml

The experiment is Gravimetric Determination of Ca2+. Please answer as many questions as you can.

Write all the balanced equations involved in this experiment.

What is the purpose of urea? Can another base like NH4OH be used instead? Why?

Why was the reaction heated (to gentle boil) after adding urea?

What is the molarity of concentrated HCl (12 M)? How would you prepare 100 mL of O.1 M dilute HCl solution from it?

What is methyl red? Why was it used?

An aqueous solution of CaC2O4 would be basic, acidic or neutral? Why?

The product on the crucible was rinsed with cold water. What is the purpose of the rinse? What will happen if hot/warm was used?

Suggest a practical use of this lab (gravimetric determination of Ca) in real world?

What is water of hydration? How/Why does it become part of a crystalline inorganic molecule?

What happens when CaC2O4.H2O is heated at >500 0C for long time?

A 10.00 mL solution containing Cl- was treated with excess AgNO3 to precipitate 0.4368 g of AgCl. What was the molarity of Cl- in the unknown? FW of of AgCl is 143.321 g/mol.

You are given a solution and asked to analyze it for the cations Ag+, Ca2+, and Zn2+. You add HCl and a white precipitate forms. You filter out the solid and add H2SO4, and nothing appears to happen. You then add hydrogen sulfide (H2S), and a black precipitate forms. Which ions should you report as being present in your solution?

A 21.31 gram sample of cobalt is heated in the presence of excess fluorine. A metal fluoride is formed with a mass of 41.93 g. Determine the empirical formula of the metal fluoride

For a Michaelis-Menten reaction, k1=5*107 M-1S-1, k-1=2*104 S-1 and k2=4*102

S-1. Calculate the Km and Ks for this reaction. Does the substrate achieve equilibrium? How would inspection of the rate constant immediately have given you the same answer

A 50 mL solution of 0.02500 M maleic acid (ka1=1.3e-2, ka2=5.9e-7) was titrated with 0.100 M NaOH. Calculate the pH after the adiition of a) 0.00 mL, b) 9.00 mL, c) 12.50 mL, d) 20.00 mL, e) 25.00 mL, and f) 26.00 mL of NaOH

4) a) Describe, in detail, why metals are good conductors of electricity.

b) How are semiconductors different from “regular” metals, and how can this be controlled to allow for modern electronics.

What is the mole fraction of ethanol in a solution made by dissolving 29.2 g of ethanol, C₂H₅OH, in 53.6 g of water?

Explain resonance stabilization from the MO perspective

first, discussion about Essential Elements

Some elements are essential to our health, like oxygen that makes up carbohydrates, fats, proteins, and DNA. Mention another two elements (essential or non-essential) and discuss their function in our body and why they are important to the well-being of human body. Do not repeat other students answers.

Second, respond for this guy he said ( There are many important elements that make up our body. One of those elements is calcium. Calcium is important because it keeps our bones and teeth strong and healthy. This gives our body skeletal structure and protects our organs. Phosphorus is another important element in the body. It works in conjunction with calcium to keep bones and teeth strong and healthy. It is also needed in the body to make protein for growth, repair, and maintenance of cells and tissues. It is very interesting how the elements are at work in our body.)

Calculate [Ag¹⁺] in solution at equilibrium when 2.39 x 10^-2 M AgNO₃ is added to 1.00 L of a 1.65 M NH₃ solution, assuming no volume change? (K_f for Ag(NH₃)₂¹⁺ is 1.1 x 10⁷)

a) 3.8 x 10^-2

b) 2.39 x 10^-2

c) 4.9 x 10^-11

d) 8.5 x 10^-10

e) 4.1 x 10^-3

Clearly and concisely explain how ionic (ion exchange) tempering of glass increases its strength (note that this is really two questions-1) what is ionic tempering? and 2) how does it affect glass properties?)

Please explain in a good words!!! Thanks