What volume of 0.250 M potassium hydroxide solution is needed to react completely with a solution containing 1.00 g of phosphoric acid?  

Expert Answers

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This is an acid-base neutralization reaction, represented by the following equation:

`3 KOH + H_3PO_4 -gt K_3PO_4 + 3 H_2O`

From the balanced equation, we can see that 3 moles of KOH react for every one mole of phosphoric acid. Here are the steps to solving the problem:

1. Find molar mass of phosphoric acid:

3(1.01) + 30.97 + 4(16.00) = 98.0 grams/mole

2. Find moles of phosphoric acid:

1.00 g H3PO4 x (1 mole/98.0g) =0.0102 moles

3. Find moles of KOH neutralized by 0.0102 moles H3PO4:

(0.0102 moles H3PO4) x (3 moles KOH/1 mole H3PO4) = 0.0306 moles KOH

4. Find volume of 0.250M KOH that contains 0.0306 moles KOH:

(M = molarity = moles of solute /1 liter of solution)

(0.0306 moles) x (1 liter/0.250 moles) = 0.122 liters  = 122 milliliters 

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