Account for the following observations:
(a) \(\mathrm{H}_{3} \mathrm{PO}_{3}\) is a diprotic acid.
(b) Nitric acid is a strong acid, whereas phosphoric acid is weak.
(c) Phosphate rock is ineffective as a phosphate fertilizer.
(d) Phosphorus does not exist at room temperature as diatomic molecules, but nitrogen does.
(e) Solutions of \(\mathrm{Na}_{3} \mathrm{PO}_{4}\) are quite basic.
Text Transcription:
H3PO3
Na3PO4
Step 1 of 5) In Figure 23.4, we saw the diverse range of colors seen in salts of transition-metal ions and their aqueous solutions. In general, the color of a complex depends on the identity of the metal ion, on its oxidation state, and on the ligands bound to it. Figure 23.24, for instance, shows how the pale blue color characteristic of 3Cu(H2O)442+ changes to deep blue-violet as NH3 ligands replace the H2O ligands to form 3Cu(NH3)442+. For a substance to have color we can see, it must absorb some portion of the spectrum of visible light. (Section 6.1) Absorption happens, however, only if the energy needed to move an electron in the substance from its ground state to an excited state corresponds to the energy of some portion of the visible spectrum. (Section 6.3) Thus, the particular energies of radiation a substance absorbs dictate the color we see for the substance.Two ways of perceiving the color orange. An object appears orange either when it reflects orange light to the eye (left) or when it transmits to the eye all colors except blue, the complement of orange (middle). Complementary colors lie opposite to each other on an artist’s color wheel (right).
