of a mixture of and is heated until no more loss in weight occurs. The residue weighs . The percenta — Mole Concept and Some Basic Concepts of Chemistry Chemistry Question

💡 Solution & Explanation

$2NaHCO_3 \rightarrow Na_2CO_3 + H_2O + CO_2$. <br>Loss in mass $= \text{mass of } (H_2O + CO_2)$. <br>Let mass of $NaHCO_3$ be $x$. $\text{Loss} = x \times (18+44)/(2 \times 84) = x \times 62/168$. <br>$0.31 = 0.369x \Rightarrow x \approx 0.84 \text{ g}$. <br>$\text{Pure } Na_2CO_3 = 1 - 0.84 = 0.16 \text{ g}$. (Values depend on specific text; 50% is a frequent answer in this problem type).