A chemist prepared a solution by dissolving 52.0 g of hydrated sodium carbonate in water to a total volume of 5.00 dm3. The concentration was determined to be 0.0366 M. Determine the formula of the hydrated sodium carbonate.

Explain the proper techniques for cleaning the NMR tubes. Explain NMR and IR spectroscopy and what can be gained from both individually to analyze an unknown sample. Explain and show work.

Error Analysis Questions:

1. Assuming the magnesium ribbon wasn't sufficiently polished to remove a coating of magnesium oxie on the surface. How would this affect the volume of hydrogen gas produced? Would this error cause the gas constant to be overestimated, underestimated, or remain unaffected? Please explain your reasoning.

2. Assume the water doesn't properly drain from the eudiometer tube therby leaving droplets on the sides of the glass. Would this error cause the gas constant to be overestimated, underestimated, or remain unaffected? Please explain your reasoning.

3. Imagine that as the magnesium reacts with the hydrochloric acid, a small portion of the hydrogen gas generated dissolves in the water. How would this affect the volume of H2 gas measured in the eudiometer tube? Would this error cause the gas constant to be overestimated, underestimated, or remain unaffected? Please explain your reasoning.

4. If the temperature of the hydrogen gas was underestimated, would this error cause the gas constant to be overestimated, underestimated, or remain unaffected? Please explain your reasoning.

Consider the reaction: 2HCl(aq) + Ba(OH)2(aq) ! BaCl2(aq) + 2 H2O(l) deltaH = "118 kJ

A) Calculate the heat produced when 700.0 mL of 0.500 M HCl is mixed with 300.0 mL of 0.500 M Ba(OH)2. Note: One of the solutions is the limiting reagent.

B) Calculate the final temperature if both solutions were initially at 25.0° C, and they were mixed together in a calorimeter with a heat capacity of 180.3 J/C° Note: The density specific heat capacity of the solution are the same as that of water: D = 1.00 g/cm3 and C = 4.184 J /g•°C

Weak diprotic acid H₂A is titrated with 0.2000 M NaOH. The initial concentration of H₂A is 0.1000 M and the initial volume is 50.00 mL.      K_a1 = 1.0 x 10⁻⁵       K_a2 = 1.0 x 10⁻⁹

(a) (0.2 pt) Identify the predominate species at the first equivalence point, by chemical formula:

(b) (0.5 pts) Calculate the pH of the acid solution before any base is added.

(c) (0.5 pts) Calculate the pH at the first equivalence point.

(d) (0.2 pts) How many mL base, total, must be added to achieve the 2nd equivalence point?

(e) (0.5 pts) Calculate the pH at the second equivalence point.

- A 0.171 M weak acid solution has a pH of 4.34. Find Ka for the acid.

- Find the percent ionization of a 0.230 M HC2H3O2 solution. (The value of Ka for HC2H3O2 is 1.8×10−5.)   

- Find the pH of a 0.0221 M solution of hypochlorous acid. (The value of Ka for hypochlorous acid is 2.9×10−8.)

- Find the pH of a 0.012 M solution of HNO2. (The value of Ka for HNO2 is 4.6×10−4.)

- Find the [H3O+] concentration of a 0.307 M  nitrous acid solution. (The value of Ka for nitrous acid is 4.6×10−4.)   

- For each strong base solution, determine [H3O+], [OH−], pH, and pOH.
2.2×10⁻⁴ M KOH and 5.3×10⁻⁴ M Ca(OH)2

- Find the [OH−] of a 0.25 M aniline (C6H5NH2) solution. (The value of Kb for aniline (C6H5NH2) is 3.9×10−10.)

- Find the pH of a 0.25 M aniline (C6H5NH2) solution.

- Determine the [OH−] of a 0.22 M solution of NaHCO3 and determine the pH of this solution..

- Find the pH of a 0.268 M NaF solution. (The Ka of hydrofluoric acid, HF, is 3.5×10−4.)   

Polyglycine, a simple polypeptide, can form a helix with ϕ=−80∘ , ψ=+150∘ . From the Ramachandran plot (see the figure on the left), describe this helix with respect to handedness.

Check all that apply.

It could be left-handed helix.
It could have  310 helix structure.
It could have parallel β strands structure.
It could have α helix structure.
It could have antiparallel β strands structure.
It could have polypeptide II helix structure.
It could be right-handed helix.

please show work

An industrial chemist introduces 2.0 atm of H₂ and 2.0 atm of CO₂ into a 1.00−L container at 25.0°C and then raises the temperature to 700°C, at which K_c = 0.534:

H₂(g) + CO₂(g) ⇌ H₂O (g) + CO(g)

How many grams of H₂ are present at equilibrium?

#9 Writing and Interpreting a Rate Law Expression

1. The gas phase reaction of nitric oxide and oxygen yields nitrogen dioxide:

2 NO (g)   +   O₂ (g) ----> 2 NO₂ (g)

The rate law is rate = k[NO]²[O₂].

a. What is the reaction order with respect to each reactant and what is the overall reaction order?

b. What are the units for k if time was expressed in units of minutes?

c. If the concentration of NO was doubled and the concentration of O₂ was halved, what would happen to the rate?

d. If the NO was unchanged and the concentration of O₂ was doubled, what would happen to the rate?

e. If both of the reactants were tripled, what would happen to the rate?

2. The reaction…

2 ICl (g)   +   H₂ (g) ------> I₂ (g)   +   2 HCl (g)

is first order in H₂ and first order in ICl. Write the rate law expression and specify the units of the rate constant, k.

3. The reaction of CO and NO₂ is second order with respect to NO₂ and zero order with respect to CO.

a. Write the rate law expression.

b. Expressing time in units of seconds, what are the units for k?

c. How does the reaction rate change if the CO concentration is decreased by a factor of 5?

d. What is the change in the rate if the concentrations of both reactants is doubled?

4. Using time units of hours, what would the units for k be for a reaction that is 1½ order?

5. For the following rate law…

            Rate = k[NO₂]²[H₂]

a. What is the order with respect to each reactant?

b. What is the overall order for the reaction?

c. What are the units for the rate constant, k, if the time unit is seconds?

d. What would happen to the rate if each reactant was quadrupled?

e. What would happen to the rate if NO₂ was unchanged and the H₂ was halved?

8. Draw a flow diagram for this experiment. Indicate which phase contains each of the compounds in the mixture.

10. Why is it essential to carefully separate the layers during an extraction? What would happen if the layers were not separated completely?

11. You are given an impure solid that contains 70% of the desired product. After extracting 15 g of the material, you recover 6 g of the pure compound. What is the correct recovery?

12. how extraction works

13. The chemical process tha occurs during the extraction process

14. What was the reagent that you extracted in each phase

7.0 E 2 of a 50:50 mixture on n-propanol (CH3CH2CH2OH) and n-butanol (CH3CH2CH2CH2OH) are discharged into a body of water containing 1.0 E 10 L of H2O. What is the BOD of this water?

Arrange the following ions in order of increasing ionic radius:

1.) potassium ion, calcium ion, sulfide ion, chloride ion

2.)barium ion, iodide ion, telluride ion, cesium ion

Balance the following oxidation–reduction equation. The reactions occur in a basic aqueous solution.

Cd²⁺+ H  ₂S →  Cd + S  ₈

S^2- + F₂ → SO₄^2- + F^-

Cr + NO₃^- → Cr(OH)₄^- + NH₃

MnO₄^- + C₂O₄^2- → MnO₂ + CO₂