Diphosphorus pentoxide reacts with water to produce phosphoric acid ( $H_{3} P O_{4}$ $H_3PO_4$ ). How do you write the balanced equation for this reaction?

Question

Diphosphorus pentoxide reacts with water to produce phosphoric acid ( $H_{3} P O_{4}$ $H_3PO_4$ ). How do you write the balanced equation for this reaction?

1 Answer

Impact of this question

75410 views around the world

You can reuse this answer
Creative Commons License

Answer 1 · 2016-01-15T00:43:04

$P_{4} O_{10(s]} + 6 H_{2} O_{(l]} \to 4 H_{3} {PO}_{4(aq]}$ $"P"_4"O"_text(10(s]) + 6"H"_2"O"_text((l]) -> 4"H"_3"PO"_text(4(aq])$

Explanation:

The interesting thing about diphosphorus pentoxide, $P_{2} O_{5}$ $"P"_2"O"_5$ , is that it usually exists as a dimer.

This implies that $P_{2} O_{5}$ $"P"_2"O"_5$ is actually the compound's empirical formula and that you should use $P_{4} O_{10}$ $"P"_4"O"_10$ as its molecular formula.

Now, diphosphorus pentoxide reacts violently with water to form phosphoric acid, $H_{3} {PO}_{4}$ $"H"_3"PO"_4$ . The reaction is highly exothermic and leads to the formation of toxic fumes.

The unbalanced chemical equation for this reaction looks like this

$P_{4} O_{10(s]} + H_{2} O_{(l]} \to H_{3} {PO}_{4(aq]}$ $"P"_4"O"_text(10(s]) + "H"_2"O"_text((l]) -> "H"_3"PO"_text(4(aq])$

To balance this equation, start by multiplying the phosphoric acid by $4$ $4$ to get equal numbers of atoms of phosphorus on both sides of the equation

$P_{4} O_{10(s]} + H_{2} O_{(l]} \to 4 H_{3} {PO}_{4(aq]}$ $"P"_4"O"_text(10(s]) + "H"_2"O"_text((l]) -> 4"H"_3"PO"_text(4(aq])$

Notice that you have $2$ $2$ atoms of hydrogen on the reactants' side and $12$ $12$ on the products' side. Multiply the water molecule by $6$ $6$ to balance the hydrogen atoms out.

Incidentally, this will also balance out the atoms of oxygen, since you'd now have $16$ $16$ on the reactants' side and $16$ $16$ on the products' side.

The balanced chemical equation for this reaction will thus be

$P_{4} O_{10(s]} + 6 H_{2} O_{(l]} \to 4 H_{3} {PO}_{4(aq]}$ $"P"_4"O"_text(10(s]) + 6"H"_2"O"_text((l]) -> 4"H"_3"PO"_text(4(aq])$

It's worth mentioning that diphosphorus pentoxide is a very powerful dehydrating agent.

SIDE NOTE You'll sometimes see this reaction written using the empirical formula of diphosphorus pentoxide, $P_{2} O_{5}$ $"P"_2"O"_5$ . In that case, the balanced chemical equation will be

$P_{2} O_{5(s]} + 3 H_{2} O_{(l]} \to 2 H_{3} {PO}_{4(aq]}$ $"P"_2"O"_text(5(s]) + 3"H"_2"O"_text((l]) -> 2"H"_3"PO"_text(4(aq])$

Science

Math

Humanities

... and beyond

Diphosphorus pentoxide reacts with water to produce phosphoric acid ( $H_{3} P O_{4}$ $H_3PO_4$ ). How do you write the balanced equation for this reaction?

1 Answer

Explanation:

Related questions

Impact of this question

Science

Math

Humanities

... and beyond

Diphosphorus pentoxide reacts with water to produce phosphoric acid (H_3PO_4H3PO4H_3PO_4). How do you write the balanced equation for this reaction?

1 Answer

Explanation:

Related questions

Impact of this question

Diphosphorus pentoxide reacts with water to produce phosphoric acid ( $H_{3} P O_{4}$ $H_3PO_4$ ). How do you write the balanced equation for this reaction?