Question

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

• A. \( 0.25 \, \text{g} \)
• 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

Step 1: Write the balanced equation for the neutralization reaction
The neutralization reaction between sodium hydroxide (NaOH) and hydrochloric acid (HCl) is: \[ \text{NaOH} + \text{HCl} \rightarrow \text{NaCl} + \text{H}_2\text{O} \] From this, we see that one mole of NaOH neutralizes one mole of HCl.
Step 2: Calculate the moles of HCl
The number of moles of HCl is given by: \[ \text{Moles of HCl} = Molarity \times Volume = 0.1 \, \text{M} \times 0.025 \, \text{L} = 0.0025 \, \text{moles} \]
Step 3: Determine the moles of NaOH required
Since the reaction is in a 1:1 molar ratio, the moles of NaOH required will be equal to the moles of HCl: \[ \text{Moles of NaOH} = 0.0025 \, \text{moles} \]
Step 4: Calculate the mass of NaOH required
To find the mass of NaOH required, we use the molar mass of NaOH: \[ \text{Molar mass of NaOH} = 40 \, \text{g/mol} \] The mass of NaOH is: \[ \text{Mass of NaOH} = \text{Moles of NaOH} \times \text{Molar mass of NaOH} = 0.0025 \times 40 = 0.1 \, \text{g} \]
Answer:
Therefore, the mass of NaOH required to neutralize 25 mL of 0.1 M HCl is \( 0.1 \, \text{g} \). So, the correct answer is option (1).