Two chemicals A and B are combined to form a chemical C. The rate, or velocity, of the reaction is proportional to the product of the instantaneous amounts of A and B not converted to chemical C. Initially, there are 100 grams of A and 50 grams of B, and for each gram of B, 2 grams of A is used. It is observed that 25 grams of C is formed in 10 minutes. How much is formed in 40 minutes? (Round your answer to one decimal place.)


What is the limiting amount of C after a long time?


How much of chemicals A and B remains after a long time?

t =  min
At what time is chemical C half-formed?

A voltaic cell consists of a Zn/Zn2+ half-cell and a Ni/Ni2+ half-cell at 25 ?C . The initial concentrations of Ni2+ and Zn2+ are 1.80M and 0.110M , respectively. The volume of half-cells is the same.

A.What is the initial cell potential?        

B. What is the cell potential when the concentration of Ni2+ has fallen to 0.600M ?        

C. What is the cell potential when the concentration of Ni2+ has fallen to 0.600M ?        

D. What is the concentration of Zn2+ when the cell potential falls to 0.45V ?

Thank you.

Nucleophilic Substitution Reactions Organic Chemistry Lab:

Explain the order of elution you observed while performing the gas chromatography for this experiment. What property of the product molecules seem to be the most important in determining relative retention times?

What is the functions of the following:

bicarbonate ion

calcium ion

chloride ion

magnesium ion

phosphate ion

potassium ion

sodium ion

sulfate ion

Thank you

Calculate the Molar Mass for the following compounds:

Fe3 (PO4)2

(NH4)2S

Zn (C2H3O2)2

Assume you have a mixture of benzophenone, diphenylmethanol and biphenyl that you have placed (spotted) on a TLC reverse phase gel (non-polar stationary phase) plate. If you developed the plate in methanol (mobile phase) which compound would have the highest R_f value? Explain your reasoning to support your answer.

1) Provide brief definitions for the following: a) conjugation; b) polymer, c) HOMO and LUMO.

2) Why do conjugated compounds absorb light in the Ultraviolet region? Why do more conjugated compounds absorb at higher wavelengths/lower energies? What is required for organic compounds to absorb in the Visible light region?

Consider a 300mL sample of 0.250M HCN (Ka=4.9x10^-10). To find the pH, do you need an ice table, can you use the Henderson-Hasselbalch equation, or something else? If an ice table, will it be a Ka or Kb equilibrium? Can you use the small x assumption? Is this a buffer? If something else, then how?

(Need Help Please!!! If possible could you work it out so i can know how to do it)

A certain weak base has a Kb of 8.00

Two 20.0-g ice cubes at –13.0 °C are placed into 295 g of water at 25.0 °C. Assuming no energy is transferred to or from the surroundings, calculate the final temperature of the water after all the ice melts.

Heat capacity of H2O(S) is 37.7 J/(mol X K); Heat Capacity of H2O(l) is 75.3 J/(mol X K); Emthalpy of Fusion of H2O is 6.01 kJ/mol

This is for a titration experiment starting with 25 ml of HCL. I've answered two but am struggling with the others.

2. Find the equivalence point on the graph. What is the equivalence volume of NaOH at this point?

The pH at the equivalence point is 8.77 and the volume of NaOH at this point is 40.00 mL of NaOH

3. a. Calculate the unknown molarity of the diluted acetic acid from the volumes of acid and base at the equivalence point and the molarity of the NaOH M_a × V_a = M_b × V_b.

b. Once you find the molarity of your diluted solution use that to calculate the molarity of the original solution using the equation M₁ × V₁ = M₂ × V₂ a second time.

4. In experiment 1, you were able to calculate the concentration of the HCl solution using the initial pH. Would this same approach work with the acetic acid? Why or why not?

What volume of 0.550 M barium hydroxide is required to neutralize 30.50 mL of 0.289 M

perchloric acid ?

A 0.249g pellet of potassium hydroxide, KOH, is added to 64.0g water in a Styrofoam coffee cup. The water temperature rises from 23.5 to 24.4 ?C. [Assume that the specific heat of dilute KOH(aq)is the same as that of water.] What is the approximate heat of solution of KOH, expressed as kilojoules per mole of KOH?

Part A:

Balance the following redox reactions occurring in acidic aqueous solution.

MnO4−(aq)+Al(s)→Mn2+(aq)+Al3+(aq)

Part B:

What mass of lead sulfate is formed in a lead-acid storage battery when 1.40 g of Pb undergoes oxidation?

Calculate the mass of solid sodium acetate and how much of 1.0 M of acetic acid required to mix with 100.0 mL to prepare a pH 4 buffer and total common ion concentration= 0.200 M (Show all work). 1. How many grams of solid sodium acetate is needed? 2. How much mL of 1.0 M acetic acid is needed?