Question

Integrated Problems #12 Common aspirin is acetylsalicylic acid, which has the structure shown below and a pKa of 3.5. The acidic hydrogen is indicated with the star. H 30: ö-H ö-C-C-H :0: H 1) What is the shape and hybridization around the carbon 1, carbon 2. oxygen 3. 2) What is the bond angle at 1, 2, 3? 3) What types of intermolecular interactions is this molecule capable? 4) Is acetylsalicylic acid a strong or weak acid? 5) Write a balanced reaction between acetylsalicylic acid and water. 6) Calculate the pH of a solution in which one normal adult dose of aspirin (6.5 X | 102 mg) is dissolved in 8.0 ounces of water. 7) What is the percent ionization of the acetylsalicylic acid?

Answer 1

Criven aspirin molecule is :06 12 bu qich UFO total we know that for hybridisation - of atoms in Molecule we have to Calculate total number of electron. pairs (sum of bond pairs and lone pairs). on the lasis of a electron pairs electron geometry of cholecules is Predicted and it lone pair of electrone is present on control atom than shape of molecule will be different from electron geometry otherwise both shape and electron - geometry will be equal. for Carlou- bond pairs electront = 3 (two c-c boud pairs and one C-H bond pain done paix electrons so Total electron pairs = 3to = 3

if total electron pair electrons is - equal to three (3) than hybridisation OF C-1 (carson-t will be spal. Electron geometry oł co will be Trigonou planar. since no lone pair electroust are Present on Carou-l than shape e of carbon will be trigonal. Planar. Bond angle for c-t equal to 1120 I lcor share of c-1 is trigonal planar, I for carbou-2 bonding pairs =3 (tc-cac-o.) lone pairs or Total electron pairs z3to=3 so hybridisation of c-2 (carbin-2) will be sp2 . Shape of 6-2 will be trigonal Planarl bcor no lone pair electrous are present Bond angle for Carbon-2 (4-2)=1120 for oxygen - Bonding pairs lone pair Total electron = 2 = 2 Pair = 2+2 = 4

IF total electron pairs is four (4) than hybridisation will be SP3. So, hybridisation for oxygen-3 = [53] if total electron pairs is four (4) than electron geometry for oxygen-3 will be tetrahedral but lone pair electrons on oxygen-3 are present so Shape of oxygen-3 wil be distorted from Zetrahedral to bent. so, shape of oxygen-3 = Ibenz a Bond angle for oxygen-3 will be equal to 110g. 5o. 2 The bond angles for carbon-to, carbou-2 and orygen-3 will be 120 120, and logoso respectively. ③ The intercholecular interactions or forces possible with aspirin molecule are dispersion i dipole - dipole interaction and hydrogen bonding. dispersion force occur when aspirin is adjacent to any other molecule we know that dipole - dipole force occur between two polar molecules. Aspirin is polar molecule.

So, when Aspirin is present heart any polar molecule such as water (Hyo) i than dipole - dipole interaction take place . Hydrogen bouding occur de tareen highly electronegative atoms of molecule! such as oxygen, Fluorine o nitrogen. and hydrogen atom of other molecule. For aspirin and water (H2o) cholecule hydrogen bonding occur between Oxygen atom of aspirin and hydrogen atoms of water or between hydrogen atoms of aspirin and oxygen atoms of water. (4) acetylsalicylic acid or Aspirin is weak acid. we know that aspirin is monoprotic acid Complete conization of askirin not take place so aspirin is weak acid and give single proton (Ht or H30) after conization.