Question

What is the mass of sodium chloride (\( \text{NaCl} \)) formed when 0.5 moles of sodium (\( \text{Na} \)) reacts with excess chlorine (\( \text{Cl}_2 \))?

• A. \( 39 \, \text{g} \)
• B. \( 35.5 \, \text{g} \)
• C. \( 29 \, \text{g} \)
• D. \( 70 \, \text{g} \)

Hint:

Remember: In a chemical reaction, the number of moles of reactants and products are related by the stoichiometric coefficients in the balanced equation. Use these relationships to convert between moles and mass.

Answer 1

The Correct Option is C

We are given the following data:

• 0.5 moles of sodium (Na)
• Excess chlorine (Cl₂)

Step 1: Write the balanced chemical equation

The balanced equation is:

\( 2 \, \text{Na} + \text{Cl}_2 \rightarrow 2 \, \text{NaCl} \)

Step 2: Determine the moles of NaCl formed

From the balanced equation, we know that 2 moles of Na produce 2 moles of NaCl. So, 0.5 moles of Na will produce 0.5 moles of NaCl.

Step 3: Calculate the mass of NaCl

The molar mass of NaCl is:

\( \text{Molar mass of NaCl} = 23 + 35.5 = 58.5 \, \text{g/mol} \)

The mass of NaCl is:

\( \text{Mass of NaCl} = 0.5 \times 58.5 = 29.25 \, \text{g} \)

Conclusion:

The mass of sodium chloride formed is approximately \( 29 \, \text{g} \).