Question

How many grams of NaOH are required to neutralize 25 mL of 0.1 M HCl solution?

• A. \( 0.1 \, \text{g} \)
• B. \( 0.5 \, \text{g} \)
• C. \( 1.0 \, \text{g} \)
• D. \( 2.0 \, \text{g} \)

Hint:

Remember: In a neutralization reaction, moles of acid = moles of base. Use this relationship to calculate the mass of the base required.

Answer 1

The Correct Option is A

Calculate the Mass of NaOH Required to Neutralize HCl

We are given the following data:

• Volume of HCl solution = 25 mL = 0.025 L
• Molarity of HCl solution = 0.1 M
• Molar mass of NaOH = 40 g/mol

Step 1: Write the balanced chemical equation

The reaction is: \[ \text{NaOH} + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} \] This indicates that 1 mole of NaOH neutralizes 1 mole of HCl. 

Step 2: Calculate the moles of HCl

The number of moles of HCl is: \[ \text{moles of HCl} = 0.1 \, \text{M} \times 0.025 \, \text{L} = 0.0025 \, \text{mol} \]

Step 3: Moles of NaOH required

Since the mole ratio of NaOH to HCl is 1:1, the moles of NaOH required are also 0.0025 mol.

Step 4: Calculate the mass of NaOH

The mass of NaOH required is: \[ \text{mass of NaOH} = 0.0025 \, \text{mol} \times 40 \, \text{g/mol} = 0.1 \, \text{g} \]

Conclusion:

The mass of NaOH required to neutralize 25 mL of 0.1 M HCl solution is 0.1 grams.