Chapter 36, Problem 4ASA

You are assigned an unknown solution that contains Group III cations. To -1 mL of this solution was added 6 M NH3 the solution was agitated to mix well, and a reddish-brown precipitate with a gelatinous solid clinging to the inner walls of the test tube was observed. The solution was centrifuged and the supernatant was tested for completeness of precipitation by adding an additional drop of 6 M NH3. No cloudiness was observed as the drop of reagent diffused through the solution. The supernatant was then carefully decanted into a clean test tube, labeled (1st solution), and saved for further testing later. The precipitate remaining in the test tube was washed with a small amount of water, centrifuged, and the wash decanted and discarded. To the precipitate was added about 10 drops of 6 M NAOH plus ~1 mL H20 and the test tube was vigorously agitated. The resulting suspension was centrifuged and the supernatant liquid was transferred to another clean test tube and clearly labeled (2nd…

Rank the following oxides in order of increasing acidity inwater: Sb₂O₃, Bi₂O₃, P₄O₁₀, Sb₂O₅.

Explain the group point, color and magnetic properties before and after oxygen binding.

1. How is complete precipitation assured in the Group III Cations? 2. In the confirmatory test of Magnesium ion, why is it necessary to heat the centrifugate in water bath for 5 minutes? 3. If Magnesium hydroxide is a white gelatinous precipitate, why is the confirmatory result indicated a blue precipitate?

In group 16, the stability of +6 oxidation state decreases and that of +4 oxidation state increases down the group. Why?

In group 16, the stability of +6 oxidations state decreases and that of +4 oxidation state increases down the group. Why?

Which statement regarding oxides is true? Correct the false statements. A. CaO is an acidic oxide because Ca2+ acts as an acid when CaO reacts with H2.B. CO2 is an acidic oxide because CO2 ionizes in H2O and O2– acts as a Lewis acid.C. MgO is a basic oxide because Mg2+ can act as a Lewis base.D. Amphoteric oxides behave as acidic oxides in the presence of H3O+.E. None of the above statements are true about oxides.

What is the dominant iron species in water samples ? What environmental factors may have contributed.  why is it necesseyy to to investigate Fe3+ concentration and total Fe concentration dpeedtaely ? Why do we need to do the sample to determine total Fe concentration ? And how did then determine Fe2+ concentration?

State reasons for the following observations: (i) The enthalpies of atomisation of transition elements are quite high. (ii) There is a greater horizontal similarity in the properties of the transition elements than of the main group elements.