This method of quantitative determination of percent purity is titrimetric reactions. These reactions most commonly involve neutralization reactions between an acid and a base. Then, we look at the neutralization reaction:
H₂C₂O₄ + 2 NaOH ⇒ Na₂C₂O₄ + 2 H₂O
So, we do the stoichiometric calculations. The important data we should know is the molar mass of oxalic acid which is equal to 90 g/mol.
(0.2283 mol/L NaOH * 0.3798 L * 1 mol H₂C₂O₄/ 2mol NaOH * 90 g/mol H₂C₂O₄) ÷ 0.7984 g *100%
= 488%
This is impossible. The purity can't be more than 100%. Looking at our calculations and the balance reaction, all steps were done correctly. So, I think there is some typographical error in the given. The mass of the sample should be 7.984 g. Then, the answer would be 48.87% purity.
3.84 - 1.43 = 2.41
2.41g of table sugar
% mass = ( (mass of element) / (total mass) ) * 100
% mass = (2.41 / 3.84) * 100
% mass = (0.6276) * 100
% mass = 62.76
62.76%
Following reactions are involved in present reaction
1) A<span>g+(aq) + Li(s) → Ag(s) + Li+(aq) </span><span>− 384.4kJ
2) </span><span>2Fe(s) + 2Na+(aq) → Fe2+(aq) + 2Na(s) + 392.3kJ
</span>3) <span>2K(s) + 2H2O(l) → 2KOH(aq) +H2(g) −393.1kJ
In above reaction, reaction 1 and 3 has negative value of </span>δh∘f, while reaction 2 has posiyive value of <span>δh∘f. As per the sign convention positive sign indicates that heat is given out during the reaction, while negative sign indicates heat is to be supplied for reaction to occur. In alternative words, product formed in reaction 2 is stable as compared to reactant. Hence, it is thermodynamically favorable. </span>
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