State the oxidation state of phosphorus in P4 and H2PO2−.

Phosphorus is a nonmetallic element that plays an important role in biological systems as a component of ATP and the sugar phosphate backbone of DNA.  Elemental phosphorus can exist in several different structural forms, known as allotropes, each exhibiting different chemical properties.  The two most common allotropes of phosphorus are P4 (white phosphorus) and (P4)n (red phosphorus).Figure 1  Structural representation of the P4 and (P4)n allotropes of phosphorusP4 is thermodynamically unstable due to its constrained geometric structure and ignites upon exposure to air.  However, the polymeric structure of (P4)n results in greater thermodynamic stability under ambient conditions.  Upon exposure to intense heat at pressures less than 43 atm, (P4)n sublimes and decomposes into P4.In an experiment, a sealed silica tube containing a sample of solid (P4)n at one end was placed under 1 atm of inert gas.  The sample was continuously heated at 450 °C until all the (P4)n had sublimed.  The resulting vapors were transferred by the inert gas to the other cooled end of the tube, where the vapors condensed into liquid P4.  Further cooling solidified the P4 product, and a 5.74 g sample was collected from the tube.  The heating curve shown in Figure 2 was subsequently obtained for the P4 sample.Figure 2  Heating curve of white phosphorus at a pressure of 1 atm (Note: Heat was supplied at a constant rate during the experiment, and the latent heat of fusion ΔHfusion was measured to be 2.51 kJ/mol.) Question 28Which of the following does NOT describe the phase behavior of P4 at 1 atm of pressure?A.At 30 °C, P4 exists as a solid.B.At 45 °C, P4 exists as a mixture of a solid and a liquid.C.At 280 °C, P4 exists as a mixture of a solid, liquid, and gas.D.At 295 °C, P4 exists as a gas.

A mole of oxygen O2 and a mole of phosphorus P4 do not contain the same number of molecules.

What is the correct electron configuration of phosphorus (P)?A.1s22s22p33s23p3B.1s22s22p63s23p3C.1s22s22p63s13p4D.1s22s22p62d5

. What is the oxidation number of phosphorous in AlPO4?+3+5+2-2

One resonance contributor to the phosphate ion is shown. When phosphate is protonated to form HPO42-, the likelihood of any of the four oxygen molecules receiving the hydrogen is equal. Which statement best explains this observation? A.The doubly bound oxygen atom is equally prone to protonation as the singly bound oxygen atoms.B.All four of the phosphate-oxygen bonds have equivalent double-bond character.C.The phosphate ion exhibits a perfectly symmetrical tetrahedral geometry.D.When solvated in aqueous media, all oxygen atoms are in close proximity to hydrogen atoms.