a) Molecular structure of ethanoic acid is given in Figure 1. What is the vibration mode number for ethanoic acid? List only bond strain vibrations of the vibration types corresponding to these modes.

b) The infrared spectrum of ethanoic acid is given in Figure 2. Write the units for the x- and y-axes of the spectrum. In which vibration frequency intervals (in cm-1) can the infrared bands corresponding to the stress vibrations asked in the case of 2-a be observed? Mark the infrared bands belonging to the two bond stress vibration modes that you selected from the bond strain vibrations.

c) OH = 1.5 D for oxygen and hydrogen bonding in the water molecule. If there is an angle of 104.4 between OH bonds, what is the magnitude (in D) and direction of the molecule's total dipole moment?

o H-C-C H O-H etanoik asit Luonth 21 1300 h=6,62606x10-34 J.S =1,0546 x10-34 J.s e =1,602 x 10-'C m H =1,0078 u mc=34,96,88 u mp=18,988 u mn=14,0067 u ID=3,336x10-30 C.m mo= 15,999 u