Some measurements of the initial rate of a certain reaction are given in the table below.

Use this information to write a rate law for this reaction, and calculate the value of the rate constant.

Round your value for the rate constant to 3 significant figures

Also be sure your answer has the correct unit symbol.

Rate = k?

k = ?

Over what pH range(s) could valine be used as an effective buffer? Explain your answer, supporting it with what we have discussed about buffers and amino acids

The hydronium ion concentration of an aqueous solution of 0.497 M triethanolamine (a weak base with the formula C6H15O3N) is ... [H3O+] = _ M

The pOH of an aqueous solution of 0.462 M caffeine (a weak base with the formula C8H10N4O2) is .

What is the pH of a solution prepared by adding 1.46g of NaNO₂ to 143.00 mL of water? (Base Ionization Constant for NaNO₂ = 2.22E-11)

1. (9 pts) Consider a buffer solution composed of C6H5NH3+ and C6H5NH2. (Kb for the amine base is 3.9 x 10-10)

a. What is the optimum buffer range for this mixture?

b. What ratio of C6H5NH2 to C6H5NH3+ would be needed to buffer a solution at pH 4.10?

c. What is the pH of a solution containing 0.35 M C6H5NH3+ and 0.45 M C6H5NH2?

d. What is the pH after addition of 0.0015 mol of HBr to 20 mL of the solution in part c?

Nitric acid and magnesium hydroxide react to form magnesium nitrate and water

A) how many moles are in 83.1 ml of 1.581M nitric acid?

B) how many moles r in 54.3ml of 1.815M magnesium hydroxide?

C) what is the limiting reactant, and what is the theoretical yield of magnesium nitrate in gram?

D) if 2.831 g of mag. Nitrate r produced in the reaction what is the percent yield

A) For the following reaction, 4.22 grams of carbon (graphite) are allowed to react with 15.1 grams of oxygen gas. carbon (graphite) (s) + oxygen (g) carbon dioxide (g) What is the maximum amount of carbon dioxide that can be formed? grams What is the FORMULA for the limiting reagent? What amount of the excess reagent remains after the reaction is complete? grams

B) For the following reaction, 60.4 grams of iron(III) oxide are allowed to react with 24.7 grams of aluminum. iron(III) oxide (s) + aluminum (s) aluminum oxide (s) + iron (s) What is the maximum amount of aluminum oxide that can be formed? grams What is the FORMULA for the limiting reagent? What amount of the excess reagent remains after the reaction is complete? grams

Quantum numbers arise naturally from the mathematics used to describe the possible states of an electron in an atom. The four quantum numbers, the principal quantum number (n),(n), the angular momentum quantum number (?),(?), the magnetic quantum number (m?),(m?), and the spin quantum number (ms)(ms) have strict rules which govern the possible values.

Identify all allowable combinations of quantum numbers for an electron.

1. n=3, ?=-2, m? = -2, ms = +1/2

2. n=3, ?=2, m? = -2, ms = -1/2

3. n=5, ?=4, m? = -1, ms = -1/2

4. n=2, ?=0, m? = 0, ms =1

5. n=1, ?=1, m? = -1, ma = -1/2

6. n=4, ?=3 m? = 4, ms = -1/2

A buffer solution is composed of 1.723 g ofKH2PO4and 5.351 g of Na2HPO4 . ( ka for dihydrogen phosphate ion is 6.2x10^-8 .)

pH =  

Mass =  g

A-What is the pH of the buffer solution?

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?

What would the pH of a solution containing 3.24g of an acid HX (Molar Mass of HX = 70.00 g/mol) after the addition of 1.49g of NaX? Assume no volume change to the solution after the addition of the NaX. (HX K_a = 1.30E-6)

write the complete balanced molecular, complete ionic and net ionic equation for the following: (All starting solutions are in a (aq) form)

- Calcium Chloride CaCl2 + Silver Sulfate Ag2SO4

- Calcium Chloride CaCl2 + Sodium Hydroxide Ag2SO4

- Cupric Bromide CuBr2 + Pottasium Chromate K2CrO4

- Cupric Bromide CuBr2 + Silver Sulfate Ag2SO4

- Pottasium Chromate K2CrO4 + Silver Sulfate Ag2SO4

- Sodium Hydroxide NaOH + Strontium NItrate Sr(NO3)2

Aqueous hydrobromic acid HBr will react with solid sodium hydroxide NaOH to produce aqueous sodium bromide NaBr and liquid water H2O. Suppose 2.4 g of hydrobromic acid is mixed with 0.876 g of sodium hydroxide. Calculate the maximum mass of sodium bromide that could be produced by the chemical reaction. Be sure your answer has the correct number of significant digits.

1.What is the pH at the equivalence point when 0.100 M weak acid HA (Ka = 1.48 x 10 - 4) is titrated with 0.050 M KOH?

2.Calculate the pH of a solution made by mixing 50.00 mL of 0.100 M KCN with 4.33 mL of 0.425 M strong acid HCl. HCN pKa = 9.21

3.Strong bases, NaOH and KOH can not be used as primary standards because of the presence of ______________ A.carbonate B.water C.adsorbed water

please explain each step by step, thank you

PLEASE ANSWER THOROUGHLY AND BREAK DOWN EACH STEP. THANK YOU!!

Characteristics of Chemical Equilibrium

The purpose of this lab is to investigate how changing various factors affect an equilibrium system. This lab consists of four independent activities. Each activity changes a component (concentration, temperature, and pressure) in an equilibrium system. Students observe how the changes affect the equilibrium system and analyze the changes using Le Chatelier’s Principle.

Please explain your answers to the following questions using Le Chatelier’s Principle.

Activity A: Nature of Equilibrium

            HIn (aq)    ↔     H⁺(aq)     +      In^– (aq)        …… (A)

            Colorless                                    Pink

            H⁺(aq)       +     OH^-(aq) →     H₂O (l)

If HCl solution is added to the solution in equilibrium A, would the solution become more pink or less pink?

If NaOH solution is added to the solution, which direction would the equilibrium shift to? Would the color become more pink or less pink when NaOH solution is added to the equilibrium?

Activity B: Effect of Concentration

            Fe³⁺⁽aq)      +        SCN^-(aq)       ↔     FeSCN²⁺(aq) ………   (B)

            yellow                     colorless                 red

            Fe³⁺(aq)       +        H₂PO₄^-(aq)   →     FeH₂PO₄²⁺(aq)

            yellow                    colorless                 colorless

Which direction would the equilibrium shift to if Fe(NO₃)₃ solution is added to the equilibrium B?

Which direction would the equilibrium shift to if Na₃PO₄ is added to the equilibrium B?

Activity C: Effect of Temperature

1. Fe³⁺⁽aq)      +       SCN^-(aq)       ↔     FeSCN²⁺(aq)       is an exothermic reaction.

yellow                 colorless                     red

Would the color of the solution become more red or less red if the temperature is increased? What happens if the temperature is decreased?

2. Co(H₂O)₆²⁺ (aq)    +     4Cl^–(aq)    ↔     CoCl₄^2- (aq)     +    6H₂O (l)

pink                                                               blue

When the solution is heated to boiling, it turns from pink to blue.

Is this reaction endothermic or exothermic?

Bonus: if AgNO₃ is added to the above blue solution, would the solution change color back to pink? If HCl is then added to the solution, would the color change again?

Activity D: Effect of Pressure

2 CO₂(g)    +      H₂O(l)   ↔   CO₂ (aq)   +   H⁺(aq)     +   HCO₃^-(aq)

The reaction forms equilibrium in a large syringe with changeable volume.

Would the solution become more acidic or less acidic when the volume is increased? What happens if the volume is decreased?