3. Chemical reactions and equilibrium constants

(a) An alternative way of writing the reaction for the dissolution of CdCO3(s) is to form the species HCO3- rather than CO32-.
Write a balanced chemical reaction for CdCO3(s) dissolution with HCO3- rather than CO32- as a product species.
Calculate an equilibrium constant and standard free energy of reaction for your new reaction. You will need to look up some equilibrium constants.

(b) How would you decide which reaction to use to describe the equilibrium of CdCO3(s) with water? From the standpoint of chemical equilibrium, does it matter? Explain.

Indicate which vibrational modes will be IR-active and Raman-active. Briefly explain.

Acetylene, symmetric triple bond stretch

Benzene, symmetric ring CC stretch

Carbon dioxide, asymmetric C=O stretch

trans 1,2 dibromoethene, sym C=C

SO3(g) can be produced by this two step process:

1.) 2FeS2 + 1 1/2 O2 = Fe2O3 + 4SO2

2.) SO2 + 1/2 O2 = So3

How many grams of SO3 can be produced from the reaction of 45.0 g of FeS2 if there is no experimental error? How many grams would actually be measured if reaction 1 had 100% yield and reaction 2 had 83.4% yield?

Predict whether aqueous solutions of the salts will be acidic, basic or neutral. Please explain why, so that I can learn the mechanism. Thank you!

Acidic Basic Neutral  (CH₃)₂NH₂NO₃
Acidic Basic Neutral  C₆H₅NH₃Br
Acidic Basic Neutral  CaBr₂
Acidic Basic Neutral  CsF₃CCOO
Acidic Basic Neutral  Cs(NO₃)

Part A

Aspirin (acetylsalicylic acid, C9H8O4) is a weak monoprotic acid. To determine its acid-dissociation constant, a student dissolved 2.00 g of aspirin in 0.600 L of water and measured the pH. What was the Ka value calculated by the student if the pH of the solution was 2.62?

Part B

A 0.100 M solution of ethylamine (C2H5NH2) has a pH of 11.87. Calculate the Kb for ethylamine.

LAB Reaction Rates

Objectives

• Evaluate the effect of concentration on the rate of a chemical reaction. ν

• Examine the effect of temperature on the rate of a chemical reaction.

Background: Many people believe that you cannot perform chemical reactions without expensive equipment or costly chemicals. But this isn’t true; chemical reactions happen everywhere. All you need is a food store to find many substances that can produce exciting chemical reactions.

Preparation

Materials

Safety Precautions

Procedure

1. Read the procedure and safety information, and complete the lab form.

2. Make data tables similar to those shown on the next page.

3. Prepare a 50 percent vinegar solution by mixing 30 mL of vinegar with 30 mL of water. This is solution A.

4. Prepare a 30 percent vinegar solution by mixing 30 mL of vinegar with 70 mL of water. This is solution B.

5. Prepare a 10 percent vinegar solution by mixing 30 mL of vinegar with 270 mL of water. This is solution C.

6. Pour the vinegar solutions into their associated 0.5-L plastic bottles labeled A, B, and C.

7. Mark a small test tube about 1–2 cm from its bottom. Fill the test tube to the line with baking soda. Pour the baking soda into one balloon.

8. Repeat step 7 with two more balloons. Be sure the amount of baking soda in each balloon is the same.

9. Place the mouth of one balloon over the mouth of one 0.5-L bottle. Do not let any of baking soda fall into the vinegar solution.

10. Repeat step 9 with the other two balloons and the remaining bottles.

Inquiry Lab

11. Lift each balloon to allow the baking soda to fall into each vinegar solution. Time how long it takes for the reaction to finish. Measure how much each balloon inflates. Record your observations in your Concentration data table.

12. Carefully remove the balloons from the bottles.

13. Rinse the plastic bottles with water.

14. Prepare a 30 percent vinegar solution by mixing

30 mL of vinegar with 70 mL of cold water.

15. Prepare two more similar solutions with room-temperature water and hot water.

16. Place the three solutions in the three 0.5-L plastic bottles.
17. Repeat steps 7 and 8 to refill the balloons with baking soda.

18. Place the balloons back on the bottles, repeating steps 9 and 10.

19. Repeat step 11. Time how long it takes for the reaction to finish.

20. Measure how much each balloon inflates. Record your observations in your Temperature data table.

Concentration Data Table (Ballon circumferrence)

Temperature Data Table (Circumferrence of ballon)

Analyze Your Data

1. Describe how increasing the concentration of a solution affects the rate of a chemical reaction. (Concentration increases rate increases)

2. Summarize how temperature affects the rate of a chemical reaction.(Temperature increases rate increases)

3. Explain why the balloons become inflated.( Because of Co2)

Conclude and Apply

4. Infer why the vinegar solutions in steps 3, 4, and 5 were different volumes. Why couldn’t the volumes be the same?

5. Predict what factors might affect the amount of product that is produced. What factors affect the rate at which products are produced?

a 4.4766g sample of petroleum product was burned in a tube furnace, and the SO2 produced was collected in 3% H202. reaction:

SO2 + H2O2 -> H2SO4

A 25ml portion of 0.00923 M NaOH was introduced into the solution of H2SO4 , following which the excess base was back-tirated with 13 33ml of 0.01007 M HCl. calculate the ppm of sulfur in the sample

Use what you learned about [H3O(+)] and pH formulas to solve the following problem

Calculate the pH of a (1.99x10^-1) M solution of Na2S03 (Kb1 = 1.56E-7, Kb2 = 5.88E-13)

1. Carbon monoxide (CO) normally binds tightly to heme (aq). How is this decreased in Mb? What are the relative CO vs. O2 binding strengths in each case?

2. Explain the role of BPG in Hb function. How is BPG involved with adaptation to high altitude? Draw and label a graph that illustrates Hb at low and high altitude.

If water is pure enough and in a sufficiently smooth container, it can sometimes be “supercooled” so that it remains liquid for a time even when its temperature is lowered below its freezing point. (For this problem, you can use table 8.2 for heat capacities and may assume that they do not change with temperature.)

(a) A beaker with 500 g liquid water initially at 10 ºC is placed in a freezer at –15 ºC, where the liquid supercools until it is at the same temperature as the freezer. Calculate qH2O, and pay careful attention to its sign.

(b) The heat of fusion of ice at 0 ºC is 6.01 kJ/mol (Table 8.3), but this number changes slightly with temperature. Calculate the heat of fusion of ice at –15 ºC.

(c) The beaker of water from part (a) (now at –15 ºC) is taken out of the freezer and jostled, which triggers the water to freeze rapidly (so quickly that the beaker is effectively insulated; no heat is transferred to or from the beaker’s surroundings). As the ice forms, heat is given off and so the temperature of the water/ice mixture rises until it reaches 0 ºC, at which point no more ice forms. How much ice will form during this process?

1) A) A samole of flourine gas is in a 12.56 L cylinder at 41.35 degree celsius and 700 torres. What is the kinetic energy and the root mean square velocity of the flourine gas.

B) Methane gas diffuses at a rate of 32.25 ml/min. Under identical conditions an unknown gas diffuses at a rate of 22.28 ml/min. What is the molar mass of the unknown gas.

C) Oxygen IS produced by the decomposition of sodium bromate and collected over water. if 76.25 ml of wet oxygen is collected at 47.5 degree celsius with an atmospheric barometric pressure of 697.2 mmHg. How many milligrams of sodium bromate have been consumed?

D) Rank the following gases from most ideal to least ideal.

IF₃ CH₄ SF₆

Calculate the pH at the equivalence point for the titration of 0.614 M B: (a weak base with pKb = 4.13) with 0.614 M HCl.

Calculate the pH at the equivalence point for the titration of 1.328 M HA (a weak acid with pKa = 6.95) with 1.328 M NaOH.

2A. The label on a 1.00-L bottle of wine states that the alcohol content is 12.5% (v/v). How much alcohol is present in the bottle?

2B. How do you make 2.50 L of 3.25 M NaHC03?

2C. How do you make 2.50 L of 0.200 M NaOH?

2D.Tell the type of solution(solid-in-liquid, etc) represented by each of the following: Gasohol, Wax in gasoline, and Gas mixture used as anesthesia

1. What is a peptide bond? 2. How does the primary structure of proteins differ from the secondary structure? A. Peptide Bonds A.1 Structure of glycylserine Structure of serylglycine A.2 Hydrolysis of serylglycine

Q.1 Why are heat and alcohol used to disinfect medical equipment?

Q.2 Why is milk given to someone who accidentally ingests a heavy metal ion such as silver or mercury?

Q.5 After working with HNO3, a student noticed that she had a yellow spot on her hand. What might be the reason?

Q.6 Which samples above give a negative biuret test? Why?

Q.7 What functional group gives a positive test in the xanthoproteic test?

Q.8 What tests could you use to determine whether an unlabeled test tube contained an amino acid or a protein?