A volume of 20.0 mL of a 0.140 M HNO3 solution is titrated with 0.850 M KOH. Calculate the volume of KOH required to reach the equivalence point.

mols HNO3 = M x L = ?

You want mols KOH to be the same.
M KOH = mols/L. You know M KOH and mols KOH , solve for L and convert to mL if desired.

To answer this question, you need to determine the moles of HNO3 and KOH reacting and then use stoichiometry to relate them. Here's how you can do it step by step:

Step 1: Write the balanced chemical equation for the reaction between HNO3 and KOH:
HNO3 + KOH -> KNO3 + H2O

Step 2: Calculate the moles of HNO3 in the given volume of the solution.
Since the concentration of HNO3 is 0.140 M and the volume is 20.0 mL (which is equal to 0.020 L), you can use the formula:
moles of HNO3 = concentration × volume
moles of HNO3 = 0.140 M × 0.020 L

Step 3: Use the stoichiometry of the balanced equation to relate the moles of HNO3 to moles of KOH.
From the balanced equation, the stoichiometric ratio between HNO3 and KOH is 1:1. This means that 1 mole of HNO3 reacts with 1 mole of KOH.

Step 4: Calculate the moles of KOH needed to react with the calculated moles of HNO3.
Since the stoichiometric ratio is 1:1, the moles of HNO3 is equal to the moles of KOH required.

Step 5: Calculate the volume of KOH required to reach the equivalence point.
To calculate the volume, you need to know the concentration of KOH. Since the concentration of KOH is given as 0.850 M, you can use the formula:
volume of KOH = moles of KOH / concentration of KOH

Now let's calculate the answer:

Step 2: moles of HNO3 = 0.140 M × 0.020 L = 0.0028 moles

Step 3: Since the stoichiometric ratio is 1:1, the moles of KOH required is also 0.0028 moles.

Step 5: volume of KOH = 0.0028 moles / 0.850 M = 0.00329 L

Therefore, the volume of KOH required to reach the equivalence point is 0.00329 L, which is equal to 3.29 mL.