Please answer each part of it. 2. Ion-cyclotron resonance experiments allow scie
ID: 1033291 • Letter: P
Question
Please answer each part of it. 2. Ion-cyclotron resonance experiments allow scientists to observe gas phase reactions of ions. In one study, (Wyatt, R.H.; Holtz, D.; McMahon, T.B.; Beauchamp, J.L. Inorg. Chem, 1974, 13, 1511-1517) it was reported that the following reaction tends to go forward: Based on the direction of this reaction, which is the stronger acid, PH3 or AsH3? Is this in agreement with the general trends for binary acids? What is the usual rationalization for this trend? What other considerations might complicate the picture from this rationalization? 3. The same study reported that the following reaction also tends to go forward: Which is the stronger acid, H2S or AsHs? Is this in agreement with the general trends for binary acids? This is an interesting example in that both the trends across the periodic table and down the periodic table are involved. Which has a greater influence, the trend across the table or the trend down the table? Does this fit with what you know about the relative acidities of binary acids of the second row (CH4, NH3, OH2, etc) and the halogen group (HF, HCl, HBr, etc.)?Explanation / Answer
Solution :
2) "AsH3 is strong acid then PH3" because PH2- is able to abstract the proton from AsH3 and we know that a acid can donate the proton and a base abstracts the proton, here AsH3 is giving the proton and stable as AsH2- .
yes it is in the agreement because in presence of strong base week base behaves as strong acid so here also AsH3 is behaving as an acid. The general trend is that, as we go down the group the P character decreases so it can donate the proton easily hence acidic strength increases down the group.
But if we talk about the Lewis basicity down the group the p character increases in the lone pair so the atom can easily donate its lone pair hence the Lewis basicity also increases down the group. so if we take Lewis basicity and bronsted acidity together this will complicate the situtation.
3) H2S is the stronger acid because here also AsH2- can abstract proton from H2S. the period has a greater influence because on across the period acidity increases and also down the group but along the period it has the greater effect.
also it fits with the trend water is more acidic then ammonia and methane is not at all acidic