Answer:
See explanation
Explanation:
The balanced redox reaction equation is;
8H+ + MnO4^- + 5Fe2+ ---------> Mn2+ + 5Fe3+ + 4H2O
Amount of KMnO4 reacted = 31.60/1000 * 0.05120 = 1.62 * 10^-3 moles
From the reaction equation;
1 mole of MnO4^- reacted with 5 moles of Fe2+
1.62 * 10^-3 moles will react with 1.62 * 10^-3 moles * 5/1 = 8.1 * 10^-3 moles
Mass of Fe2+ reacted = 8.1 * 10^-3 moles * 56 g/mol
Mass of Fe2+ reacted = 0.45 g
Amount of iron in the sample = 0.45 g
Percentage of iron in the sample;
0.45 g/4.230 g * 100 = 10.6 %
Answer:
The expression to calculate the mass of the reactant is 
Explanation:
<em>The amount of heat released is equal to the amount of heat released per gram of reactant times the mass of the reactant.</em> To keep to coherence between units we need to transform 1,080 J to kJ. We do so with proportions:

Then,
