Problem 34 - Chemistry: The Central Science

Question

Write the chemical formula for each of the following compounds, and indicate the oxidation state of the halogen or noble-gas atom in each: (a) chlorate ion, (b) hydroiodic acid, (c) iodine trichloride, (d) sodium hypochlorite, (e) perchloric acid, (f) xenon tetrafluoride.

Step-by-Step Solution

Answer

(a) Chlorate ion: Formula = \(ClO_3^-\), Chlorine oxidation state = +5 (b) Hydroiodic acid: Formula = HI, Iodine oxidation state = -1 (c) Iodine trichloride: Formula = ICl_3, Iodine oxidation state = +3 (d) Sodium hypochlorite: Formula = NaOCl, Chlorine oxidation state = +1 (e) Perchloric acid: Formula = HClO_4, Chlorine oxidation state = +7 (f) Xenon tetrafluoride: Formula = XeF_4, Xenon oxidation state = +4

Step 1: (a) Chlorate ion

The chlorate ion consists of a central chlorine atom bonded to three oxygen atoms via single bonds and carries a -1 charge. So, its chemical formula is \(ClO_3^-\). To find the oxidation state of chlorine, we can use the formula: Oxidation state of chlorine + (3 x Oxidation state of oxygen) = Charge on the ion Here, the oxidation state of oxygen is -2. Substituting the values: Oxidation state of chlorine + (3 x -2) = -1 The oxidation state of chlorine in the chlorate ion is +5.

Step 2: (b) Hydroiodic acid

Hydroiodic acid is a compound formed by the combination of hydrogen and iodine. The chemical formula is HI. In this case, the oxidation state of hydrogen is +1. Since the compound is neutral (no charge): Oxidation state of iodine + 1 = 0 The oxidation state of iodine in hydroiodic acid is -1.

Step 3: (c) Iodine trichloride

Iodine trichloride is formed by the combination of one iodine atom and three chlorine atoms. The chemical formula is ICl_3. To find the oxidation state of iodine, we use the formula: Oxidation state of iodine + (3 x Oxidation state of chlorine) = 0 Since the oxidation state of chlorine is -1: Oxidation state of iodine + (3 x -1) = 0 The oxidation state of iodine in iodine trichloride is +3.

Step 4: (d) Sodium hypochlorite

Sodium hypochlorite is a compound formed by the combination of one sodium, one oxygen, and one chlorine atom. The chemical formula is NaOCl. The oxidation states of sodium and oxygen are +1 and -2, respectively. So, considering the compound is neutral: 1 + (-2) + Oxidation state of chlorine = 0 The oxidation state of chlorine in sodium hypochlorite is +1.

Step 5: (e) Perchloric acid

Perchloric acid is a compound formed by the combination of one hydrogen atom, one chlorine atom, and four oxygen atoms. The chemical formula is HClO_4. The oxidation state of hydrogen is +1 and that of oxygen is -2. So, considering the compound is neutral: 1 + Oxidation state of chlorine + (4 x -2) = 0 The oxidation state of chlorine in perchloric acid is +7.

Step 6: (f) Xenon tetrafluoride

Xenon tetrafluoride is a compound formed by the combination of one xenon atom and four fluorine atoms. The chemical formula is XeF_4. The oxidation state of fluorine is -1. To find the oxidation state of xenon, we use the formula: Oxidation state of xenon + (4 x -1) = 0 The oxidation state of xenon in xenon tetrafluoride is +4.