Organic Chemistry - Assignment Example

The carboxylic group will exhibit the hydrogen intermolecular bonds due to the presence of the hydrogen molecule while the amino group will exhibit the ionic intermolecular bonds since they form the ions and could also use the van der Waals at times.

The receptor needs to have an amino complementary functional group for bonding to occur since molecular bonding must include ionic molecular bonds.  Without this, the interaction cannot occur.

(c)  The −NH2 group on Compound B can react with benzoic acid, shown in Figure 3.

Figure 3 Benzoic acid.

Draw the product of this reaction, name the new functional group produced, state the type of reaction that has occurred, name any other products of the reaction and briefly explain how you arrived at your answer.

C6H5COOH + R-NH2 → C6H5CONH-R + H2O
Benzoic Acid + Compound B → a benzamide + water

The functional group created is an amide. The reaction is a condensation reaction since two functional groups combine to form one and produce water.

(d)  Compound C, shown in Figure 4, can be produced from Compound B using a chemical process known as dehydrogenation (meaning ‘removal of hydrogen’).

Figure 4 Compound C.

The presence of the double bond (C=C) in Compound C means that the molecule can exist in two different forms, identified by the prefix cis or trans, depending upon the arrangement of the functional groups and hydrogen atoms around the double bond. Draw the two possible forms of Compound C showing the positions of the functional group and hydrogen atoms. Assign each the appropriate prefix that would distinguish one from the other and briefly explain what these prefixes indicate.

Question 2,

(a)  

Equal moles of nitric acid (HNO3) and formic acid (HCOOH) were each dissolved in equal volumes of water. State and explain which of the resulting solutions would have the higher ph. Your answer should include an explanation of the terms strong acid and weak acid and a definition of ph. 

            The solution formed by Nitric acid and water would have a higher pH than that formed by Formic acid. Nitric acid will give a solution of higher pH than Formic acid. The reason can be explained by the knowledge that stronger acids like Nitric acid tend to give higher pH than weak acids like Formic acid due to the difference in their breakdown and disintegration processes. Strong acids break down in water hence their pH is higher since the levels of acidity are low. Weak acids fail to break down completely maintaining a given level of acidity hence the lower ph. The known different categorizes these strong and weak acids their ability to dissociate in water. Strong acids give up protons more readily than weak acids. It is also noteworthy that strong acids have a concentration of H+ ions that is equal to the concentration of the acid. For weak acids however, the concentration of H+ ions is less than that of the acid itself.

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  Formic acid dissociates in water as shown in Reaction 3.

Question 2,

The equilibrium constant (Ka) for Reaction 3 at 25 °C is 1.80 × 10−4 mol dm−3. Calculate the equilibrium concentration of hydrogen ions if the concentration of formic acid at equilibrium is 0.00500 mol dm−3.

 (Show all of your working and give your answer to three significant figures, in correct scientific notation.)