The hint tells you how to work the problem.
mols NaOH = M x L = ?
mols acid = mols NaOH since it is 1:1 ratio.
Then M acid = mols acid/L acid = ?
(Hint: Find the moles of NaOH from the given molarity and volume. mols of NaOH = mols of acid. Knowing mols and volume of acid, calculate molarity of the acid)
mols NaOH = M x L = ?
mols acid = mols NaOH since it is 1:1 ratio.
Then M acid = mols acid/L acid = ?
Step 1: Calculate the moles of NaOH using the given molarity and volume.
Moles of NaOH = Molarity * Volume
Moles of NaOH = 0.14 M * 17.50 mL
Step 2: Since NaOH and the unknown acid react in a 1:1 ratio, the moles of NaOH will be equal to the moles of the acid.
Moles of acid = Moles of NaOH
Step 3: Calculate the molarity of the acid by dividing the moles of acid by the volume in liters.
Molarity of acid = Moles of acid / Volume (in liters)
Volume (in liters) = Volume (in mL) / 1000
Molarity of acid = Moles of acid / (Volume (in mL) / 1000)
Let's plug in the given values and calculate it:
Moles of NaOH = 0.14 M * 17.50 mL
Moles of acid = Moles of NaOH
Volume (in liters) = 25.0 mL / 1000
Molarity of acid = Moles of acid / (Volume (in mL) / 1000)
Now, let's calculate it step by step:
Step 1: Moles of NaOH
Moles of NaOH = 0.14 M * 17.50 mL
Moles of NaOH = 0.14 * 0.0175 mol
Moles of NaOH = 0.00245 mol
Step 2: Moles of acid
Since NaOH and acid react in a 1:1 ratio,
Moles of acid = Moles of NaOH
Moles of acid = 0.00245 mol
Step 3: Molarity of acid
Volume (in liters) = 25.0 mL / 1000
Volume (in liters) = 0.025 L
Molarity of acid = Moles of acid / (Volume (in mL) / 1000)
Molarity of acid = 0.00245 mol / 0.025 L
Molarity of acid = 0.098 M
So, the molarity of the unknown acid is 0.098 M.