Question

General Chemistry II Part 3. Now let's consider the effect of structure on acid-base properties: There are two main factors that determine whether a molecule containing X-H bond will behave as a Bronsted-Lowry acid and donate a proton: the strength of the bond and the polarity of the bond. On one hand, the stronger the X-H bond, the lower the molecule's tendency to donate the proton. On the other hand, the more polar the X-H bond, the higher the molecules tendency to donate the proton. Many substances that contain H-O-X grouping will function either as acids or as bases. When O-X bond is lonic, the substance behaves as a base, releasing OH-ions in water (eg NaOH). Molecules in which the O-X bond is strong and covalent tend to behave as acids. And as X becomes more electronegative, the acid becomes stronger. The polarity of the 0-X bond can also be changed by addition of other oxygen atoms to the X atom (eg. HOBr is a weak acid, but HOBro, is a strong acid). XH bond strength Atom Electronegativity /nal 3. Consider the following set of acids: HF, HC, HB, HI a) Use the data presented in the table to explain why HF(aq) is a weak acid while HCl(aq), HBr(aq), and Hl(aq) are all strong acids. 2.1 432 30 35 411 386 459 565 4.0 427 3.0 2.8 363 295 b) Explain why CH3OH does not dissociate in solution and H.co, does it is a weak acid). C) Range the following acids from the strongest to the weakest: HOCIO, HOCL, HOCIOS Explain you reasoning MacBook Pro

Answer 1

The answer to this is as below-

According to the data provided in the table CHF) bond strength = 565 kJ/mol, ICH-ul) bond strength = 427 kJ/mol, (M-Br) bond strength=363 kJ/mol, (H-I bond strength= 295 kJ/mol * A acid is said to be stronger if it easily gives ut in aqueous media. M-X Ht txo Thus, it reauires a lot of energy to produce Ht from HF as compared to Mel B Br and HI. Due to this reason HF is weak acid as compared to HI, MB5 and HCl. dots. ChoH Because does not dissociate in solution but H0 Hooldoh - Hood_8+ HO In case of M203, the anion formed after removal of it is stablized by electron widthdrawing group (nere- &-) while in case of CH₂OH, CH₂OH Mt + 8 No electron withdrawing group is present, this anion formed is not stabliald, so it does not dissoclate in soln I © = Hoclo, > Hollo> HOCL, (strong to weave acid) 03 bu cah Ho!! Hollo, after removal of it is stablized by resmance Holto also stablized by resonance but less Holl Mo Stablieation by resonance.