Sodium tripolyphosphate is used in detergents to make them effective in hard water. Calculate the oxidation number of phosphorus in Na₅P₃O₁₀.

Question

Quizplus · Accepted Answer

In the compound, the oxidation number of sodium is +1 and the oxidation number of oxygen is -2. Since the compound is neutral, the sum of the oxidation numbers of all the elements is zero. Therefore, the sum of the oxidation numbers of sulfur is 0 and the sum of the oxidation numbers of phosphorus must also be 0. Since there are 5 oxygen atoms, and each oxygen atom has an oxidation number of -2, the total oxidation number contributed by oxygen is -10. Therefore, the oxidation number of phosphorus must be +5 to balance out the sum of the oxidation numbers.

Sodium Tripolyphosphate Is Used in Detergents to Make Them Effective