E is a solution of dibasic acid H2X containing 3.25g per 250cm^3 of solution F is 120mol/dm^3 of KOH solution ,calculate the average volume if E used

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To calculate the average volume of solution E used, we need to know the molar mass of dibasic acid H2X. Unfortunately, this information is not provided in the question.

To calculate the average volume of solution E used, we need to determine the number of moles of H2X in the solution.

First, let's calculate the number of moles of H2X in solution E. We'll use the formula:

Number of moles = Mass (g) / Molar mass (g/mol)

The molar mass of H2X needs to be known to perform this calculation. Let's assume for this example that the molar mass of H2X is 100 g/mol.

Number of moles of H2X = Mass of H2X / Molar mass of H2X
= 3.25 g / 100 g/mol
= 0.0325 mol

Now that we know the number of moles of H2X in solution E, we can use stoichiometry to determine the amount of KOH required to react with these moles of H2X.

From the balanced chemical equation:
H2X + 2KOH → K2X + 2H2O

We can see that 1 mole of H2X reacts with 2 moles of KOH.

Number of moles of KOH required = (0.0325 mol H2X) × (2 mol KOH / 1 mol H2X)
= 0.065 mol KOH

Now, let's calculate the volume of solution F (KOH) required to have 0.065 moles of KOH.

Molarity is defined as the number of moles of solute per liter of solution:

Molarity (mol/L) = Number of moles / Volume (L)

Volume (L) of solution F = Number of moles of KOH / Molarity of solution F
= 0.065 mol / 120 mol/dm^3
= 0.000542 dm^3

Since 1 dm^3 is equal to 1000 cm^3, we can convert the volume to cm^3:

Volume (cm^3) = 0.000542 dm^3 × 1000 cm^3/dm^3
= 0.542 cm^3

Therefore, the average volume of solution E used is approximately 0.542 cm^3.