Problem 63
Write a molecular formula for each compound, and indicate the oxidation state of the group \(5 \mathrm{~A}\) element in each formula: (a) phosphorous acid, (b) pyrophosphoric acid, (c) antimony trichloride, (d) magnesium arsenide, (e) diphosphorus pentoxide.
Problem 64
Write a chemical formula for each compound or ion, and indicate the oxidation state of the group 5 A element in each formula: (a) phosphate ion, (b) arsenous acid, (c) antimony(III) sulfide, (d) calcium dihydrogen phosphate, (e) potassium phosphide.
Problem 65
Account for the following observations: (a) Phosphorus forms a pentachloride, but nitrogen does not. (b) \(\mathrm{H}_{3} \mathrm{PO}_{2}\) is a monoprotic acid. (c) Phosphonium salts, such as \(\mathrm{PH}_{4} \mathrm{Cl}\), can be formed under anhydrous conditions, but they can't be made in aqueous solution. (d) White phosphorus is extremely reactive.
Problem 66
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.
Problem 67
Write a balanced equation for each of the following reactions: (a) preparation of white phosphorus from calcium phosphate, (b) hydrolysis of \(\mathrm{PBr}_{3}\), (c) reduction of \(\mathrm{PBr}_{3}\) to \(P_{4}\) in the gas phase, using \(\mathrm{H}_{2}\).
Problem 68
Write a balanced equationfor each of the following reactions: (a) hydrolysis of \(\mathrm{PCl}_{5}\), (b) dehydration of phosphoric acid (also called orthophosphoric acid) to form pyrophosphoric acid, (c) reaction of \(\mathrm{P}_{4} \mathrm{O}_{10}\) with water.
Problem 69
Give the chemical formula for (a) hydrocyanic acid, (b) nickel tetracarbonyl, (c) barium bicarbonate, (d) calcium acetylide.
Problem 70
Give the chemical formula for (a) carbonic acid, (b) sodium cyanide, (c) potassium hydrogen carbonate, (d) acetylene.
Problem 71
Complete and balance the following equations: (a) \(\mathrm{ZnCO}_{3}(s) \stackrel{\Delta}{\longrightarrow}\) (b) \(\mathrm{BaC}_{2}(\mathrm{~s})+\mathrm{H}_{2} \mathrm{O}(l) \longrightarrow\) (c) \(\mathrm{C}_{2} \mathrm{H}_{2}(g)+\mathrm{O}_{2}(g) \longrightarrow\) (d) \(\mathrm{CS}_{2}(g)+\mathrm{O}_{2}(g) \longrightarrow\) (e) \(\mathrm{Ca}(\mathrm{CN})_{2}(s)+\operatorname{HBr}(a q) \longrightarrow\)
Problem 72
Complete and balance the following equations: (a) \(\mathrm{CO}_{2}(g)+\mathrm{OH}^{-}(a q) \longrightarrow\) (b) \(\mathrm{NaHCO}_{3}(s)+\mathrm{H}^{+}(a q) \longrightarrow\) (c) \(\mathrm{CaO}(s)+\mathrm{C}(s) \stackrel{\Delta}{\longrightarrow}\) (d) \(\mathrm{C}(s)+\mathrm{H}_{2} \mathrm{O}(g) \stackrel{\Delta}{\longrightarrow}\) (e) \(\mathrm{CuO}(s)+\mathrm{CO}(g) \longrightarrow\)
