An unknown compound, X, is known to possess two groups that ionize as the pH changes. One of these groups is a carboxylate with a pKa of 2.0. When 100 mL of 0.1 M NaOH is added to 100 mL of 0.1 M solution of X at pH 2.0, the pH increases to 6.72. What is the pKa of the second ionizable group of X?

A. 4.33

B. 6.72 CORRECT ANSWER

C. 7.20

D. 8.55

E. 9.76

Please show how B. is the correct answer

Buffer capacity is a measure of a buffer solution\'s resistance to changes in pH as strong acid or base is added. Suppose that you have 125 mL of a buffer that is 0.400 M in both propanoic acid (C2H5COOH) and its conjugate base (C2H5COO–). Calculate the maximum volume of 0.290 M HCl that can be added to the buffer before its buffering capacity is lost.

If you leave in Northern Florida that the annual average temperature outside changes on the minimum to 40 F and Summer to 80 F, to save energy, is it better to turn off your water heater and turn it on 1 hour before shower or use, or let it to be on all the time. The water set temperature is normally around 110 F. Show with detail calculations if there is any energy saving.

Have there been any significant changes in Australia's terms of trade with China and Japan? In the last 20 years, why? for example?

You are studying how changes in blood pH might be controlled by homeostasis. In a trial, you let a mouse run on a treadmill for a fixed period of time, and then you measure its blood pH. Intriguingly, you observe the blood pH drops (more acidic) as carbon dioxide is released into the bloodstream. Which component of the homeostatic feedback system is responsible for producing the correct response if the blood pH is far enough from normal that a response is necessary?

.What are protein conformational changes and describe FIVE examples of their involvement in any aspect of signal transduction. One of the examples MUST be the involvement of kinases.

Describe the stages of the cell cycle and what happens in each stage, making sure to include what is happening to the DNA. For M phase, describe all stages. If you were looking at cells under the microscope, what would you use as a distinguishing feature for each stage.

19.A mutation that changes an amino acid-coding codon to a stop codon is classified as:

A – Silent

B – Missense

C – Nonsense

D – Neutral

20.Spontaneous mutations can arise from:

A – All answers are correct

B – A base gets damaged

C – DNA polymerase inserts an incorrect nucleotide

D – A loop occurs during replication

21.DNA Repair Systems:

A – Counteract spontaneous and induced mutations

B – Counteract induced mutations only

C – Counteract amino acid changes introduced by mutations

D – Prevent DNA damage

22.Which of the following general mechanisms appear to be involved in the formation of cancer cells?

A – Genomic instability, DNA repair failure, chromatin modifications

B – RNA failure, DNA phosphorylation, phosphorylation of adenyl cyclase

C – Transdetermination, mutation, allosteric interactions

D – Inversions, operon formation, methylation

23.Mutations in the ras gene family induce normal cells to proceed into the replication cycle. This convert the ras gene from a ____ gene to a ____ gene.                                         

A – Mutant; oncogene

B – Proto -oncogene; oncogene

C – Tumor suppressor; proto-oncogene

D – Oncogene; proto-oncogene

24.What is a potential carcinogen?

A – Any substance that damages DNA

B – Any pollutant

C – Any toxic chemical

D – Any chemical

A moderator effect occurs when the moderator (an independent variable or construct) changes the strength or even the direction of a relationship between two constructs in the model. There are two types of moderating relationships: continuous and categorical.

Analyze ONE (1) major difference between continuous and categorical moderating relationships.

Following thermal changes in a material's environment, name a method that may be used in conjunction with thermal analysis to give more insight of a material's chemical and physical response mechanism? Explain how it could be used.