By dissolving the acidic oxide in water, phosphoric acid was obtained

By dissolving the acidic oxide in water, phosphoric acid was obtained with a chemical amount of 3 mol. State the chemical amount of acidic oxide reacted.

Let’s write down given:

n (H3PO4) = 3 mol

n (acidic oxide) -?

Solution.

To obtain phosphoric acid, it is necessary to dissolve acidic oxide – phosphorus (V) oxide – P2O5 in water.

Let’s write the reaction equation:

P2O5 + H2O = H3PO4

P2O5 + H2O = H3PO4

Let’s arrange the coefficients:

P2O5 + 3 H2O = 2 H3PO4

Let’s compose the ratio:

According to the reaction equation, to obtain 2 mol (H3PO4), 1 mol (P2O5) is required;

To obtain 3 mol (Н3РО4), x mol (Р2О5) is required, hence:

X mol (Р2О5) = 1 mol (Р2О5) * 3 mol (Н3РО4) / 2 mol (Н3РО4)

X mol (P2O5) = 1.5 mol

Answer: to obtain 3 mol of Н3РО4, it is necessary to take 1.5 mol of Р2О5.