- Answer the following questions about acids 1- What is the phase of a.docx
- 1. . Answer the following questions about acids 1. What is the phase of all acids? 2. What is the smallest particle to represent an acid? 3. What kind of bond holds acids together? Defend your answer Solution Ans. #1. All acids are present in aqueous phase . # An acid (Arrhenius – Bronsted Lowry acid) is a chemical species that donates a H + . To donate an H + , the acid must be in contact with a H + -acceptor. For most of the acids that we encounter, water acts as a medium or acceptor. Therefore, all acids are present in aqueous phase so that acid molecule can donate an H + -ion to the medium. #2. H + ion is the smallest ion present in an acid. An acid has a general formula of AH – where A is an element (say, Cl) or a group (NO 3 ). In all case, H + ion or H-atom constitutes the smallest particle of an acid because there is no other element in the periodic table smaller than an H-atom. #3. Because of greater difference in the electronegativity of the acidic H-atom and A, the acid molecule has relatively positive charge center at the H-atom, and a negative charge center at the A atom group. So, the bond between H + and A atom/group is relatively polar covalent bond . # The acid molecules may be held together by intermolecular H-bonds (HNO 3 , H 2 SO 4 , HClO 4 , etc. oxoacids), or dipole-dipole attractions (HCl, HCN, HBr, etc.) or other forces depending on the nature of the acid molecule. # Hydrogen bond is a weak attractive force between a highly electronegative atoms (O, N, F) and a H-atoms linked to such atoms. The criteria for H-bonds formation is that there must be - I. A highly electronegative atom ( F, N, O -atom), and II. A H-atoms linked to such atoms (F, N, O).