Yeast are unicellular eukaryotic organisms that have been utilized for thousands of years to produce leavened (risen) bread and alcoholic beverages. To make leavened bread yeast are added to the bread dough and once it is placed in a warm place, the yeast cause the bread to rise. Knowing what you do about glycolysis and the fates of pyruvate, explain biochemically why the bread rises.

An aqueous solution containing 1.00 g of oxobutanedioc acid (FM 132.07) per 100 mL was titrated with 0.09432 M NaOH.

1. Calculate the pH at th following volumes of added base: 0.5V_e1, V_e1, 1.5V_e2, V_e2, 1.05V_e2
2. Sketch the titration curve, using the values calculated above.
3. Which equivalence point would be best to use in this titration (which one is not blurred)?

Ka1 = 2.56

Ka2 = 4.37

Ve1 = equivalence point 1

Ve2 = equivalence point 2

1. Sketch a proposed set up for the hot bath. Make sure that all of the listed equipment is included in the sketch (the drawing does not have to be of professional quality, of course.)

2. Calculate the theoretical yield of aspirin if 1.05 g of salicylic acid is combined with 2.0 mL of acetic anhydride. Follow your Result Sheet if you need help.

3. What is an ester?

4. Why is sulfuric acid added to the esterification reaction?

Can you detect any trends in formula, mass and boiling point bp in going down this series of molecules? What would you predict as a rule for determining bp? Can you support your hypothesis?

22 Pre-Lab Study Questions

1. What happens to glucose or galactose when the Cu²⁺ in Benedict’s reagent is reduced?

2. Would you expect fructose or glucose to form a red color rapidly with Seliwanoff’s reagent? Explain your answer.

3. Why don’t all the disaccharides undergo fermentation with yeast?

4. How can the iodine test be used to distinguish between amylose and glycogen?

Which of the following reactions is properly classified as a precipitation, reduction/oxidation, and/or Bronsted-Lowry acid/base reaction? (1) CH3COOH(aq) + OH− (aq) → H2O(l) + CH3COO− (aq) is both precipitation and acid/base (2) CH4(g) + 2 O2(g) → CO2(g) + 2 H2O(g) is both redox and acid/base (3) 2 H3O + (aq) + CaCO3(s) → Ca2+(aq) + CO2(g) + 3 H2O(l) is both redox and acid/base (4) 2 Na(s) + Cl2(g) → 2 NaCl(s) is both precipitation and redox (5) None of the above please explain why because i thought it would be A

Please balance the following redox equation using half reactions. Show work.

___ NaOH + ___ Ca(OH)₂ + ___ C + ___ ClO₂ ---> ___ NaClO₂ + ___ CaCO₃ + ___ H₂O

Do you think that eggs are healthy food? Explain using the appropriate chemistry terminology, and provide at least two references to support your arguments.

1. A 0.17-mole sample of nitrogen gas occupies a volume of 2.80 L . What is the volume of 0.29 mol of nitrogen gas under the same conditions? Express your answer using two significant figures. V=

2. A sample of gas with an initial volume of 32.0 L at a pressure of 760 mmHg and a temperature of 320 K is compressed to a volume of 16.3 L and warmed to a temperature of 445 K . What is the final pressure of the gas? Pfinal =

3.

6. Use the combined gas law to complete the following table (assume the number of moles of gas to be constant): . Complete each column

1) Rank the following from the strongest acid to the weakest acid. Explain with reasons please.
A) CH3CH2OH
B) CH3OCH3
C) CH3—NH—CH3
D) CH3—C≡CH
E) CH3—CH=CH2

2) Draw all possible isomers that have the molecular formula C5H12O and name them using the systematic IUPAC name.

3) The following compound has 2 isomers. One isomer has a dipole moment of 0 D, whereas the other has a dipole moment of 2.95 D. Propose structures for the 2 isomers that are consistent with these data. ClCH=CHCl

1. can ice be melted merely by applying pressure? how about dry ice? Explain your answers.
2. explain how the solid liquid line in the phase diagram of water differs in character from the solid liquid line in the phase diagrams of most other substances such as CO2.
3. which phase of a substance (gas, liquid or soild) is most likely to be the stable phase:(A) at low temperature and high presumes (b)at high temperature and low pressure?
4. at what temperature and pressures does a substance behave as a supercritical fluid?
5. explain why a needle floats on the surface of water but sinks in a container of methanol?
6. explain why the plumbing in a house may burst If the temperature in the house drops below O°C?
7. a hot needle sinks when placed on the surface of cold water but a cold needle floats why?
8.what kind of intermoloccular force must be overcome as (a) soild CO2 sublime (b) CHC13 boils (c) ice melts?

The oxidation of copper(I) oxide, Cu2O(s), to copper(II) oxide, CuO(s), is an exothermic process,

2Cu2O(s) + O2(g) ----> 4CuO(s) Delta H (reaction)= -292.0 Kj/ mol

Calculate the energy released as heat when 9.67 g of Cu2O(s) undergo oxidation at constant pressure.

How much 6.0M NaOH must be added to .500 L of a buffer that is .0200M acetic acid and .025 M sodium acetate to raise the pH to 5.75 at 25C?

In which of the following pairs of bonds is the shorter bond length not followed by the longer bond length?

1. Describe below (briefly) a) the motivation for hybridization in valence bond theory and b) why valence bond theory cannot predict magnetism. In your answer, make sure to include a description of how molecular orbital theory addresses magnetism.