Question

100 mL of 1.0 M HCl are mixed with 75 mL of 1.0 M \(Na_2CO_3\). The resulting solution will be:

• A. acidic
• B. basic
• C. neutral
• D. amphoteric

Hint:

Always compare required vs available moles using balanced equation.

Answer 1

The Correct Option is B

Concept: Neutralization: \[ Na_2CO_3 + 2HCl \rightarrow 2NaCl + H_2O + CO_2 \]

Step 1: Moles.
\[ n_{HCl} = 0.1 \times 1 = 0.1 \] \[ n_{Na_2CO_3} = 0.075 \times 1 = 0.075 \]

Step 2: Stoichiometry.
\[ 1 \text{ mol } Na_2CO_3 \text{ needs } 2 \text{ mol HCl} \] Required HCl: \[ 0.075 \times 2 = 0.15 \] Available HCl = 0.1 → insufficient

Step 3: Conclusion.
\(Na_2CO_3\) remains → solution is basic.