Question

Вычислите массу гидроксида калия, необходимую для полной нейтрализации 25.2 фосфорной кислоты.

Answer 1

Ответ:

на фото решение:

Объяснение:

Answer 2

Calculating the Mass of Potassium Hydroxide Needed

To calculate the mass of potassium hydroxide needed to neutralize 25.2 grams of phosphoric acid, we can use the balanced chemical equation for the neutralization reaction between phosphoric acid and potassium hydroxide.

The balanced chemical equation for the reaction is:

H3PO4 + 3KOH → K3PO4 + 3H2O

From the balanced equation, we can see that 1 mole of phosphoric acid (H3PO4) reacts with 3 moles of potassium hydroxide (KOH).

Now, let's calculate the molar mass of phosphoric acid (H3PO4) and potassium hydroxide (KOH) to proceed with the calculation.

The molar mass of phosphoric acid (H3PO4) is: - Hydrogen (H): 1.01 g/mol - Phosphorus (P): 30.97 g/mol - Oxygen (O): 16.00 g/mol (x 4)

Molar mass of H3PO4 = (1.01 x 3) + 30.97 + (16.00 x 4) = 97.99 g/mol

The molar mass of potassium hydroxide (KOH) is: - Potassium (K): 39.10 g/mol - Oxygen (O): 16.00 g/mol - Hydrogen (H): 1.01 g/mol

Molar mass of KOH = 39.10 + 16.00 + 1.01 = 56.11 g/mol

Now, we can calculate the amount of potassium hydroxide needed to neutralize 25.2 grams of phosphoric acid.

Step 1: Calculate the moles of phosphoric acid using its molar mass. - Moles of H3PO4 = Mass / Molar mass - Moles of H3PO4 = 25.2 g / 97.99 g/mol

Step 2: Use the mole ratio from the balanced chemical equation to find the moles of potassium hydroxide needed. - Moles of KOH = Moles of H3PO4 x (3 moles KOH / 1 mole H3PO4)

Step 3: Convert the moles of potassium hydroxide to grams using its molar mass. - Mass of KOH = Moles of KOH x Molar mass of KOH

Let's calculate the mass of potassium hydroxide needed based on the above steps.

Step 1: Moles of H3PO4 = 25.2 g / 97.99 g/mol = 0.257 moles (approx)

Step 2: Moles of KOH = 0.257 moles x (3 moles KOH / 1 mole H3PO4) = 0.771 moles (approx)

Step 3: Mass of KOH = 0.771 moles x 56.11 g/mol = 43.28 grams (approx)

So, the mass of potassium hydroxide needed to neutralize 25.2 grams of phosphoric acid is approximately 43.28 grams.

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