At 25$^\circ$C, 50 g of iron reacts with HCl to form FeCl2. The evolved hydrogen gas expands against a constant pressure of 1 bar. The work done by the gas during this expansion is _________ J. (Round off to the Nearest Integer).
[Given : R = 8.314 J mol$-$1 K$-$1. Assume, hydrogen is an ideal gas] [Atomic mass of Fe is 55.85 u]
Answer (integer)
2218
Solution
$Fe + 2HCl \to FeC{l_2} + {H_2}$<br><br>${{50} \over {55.85}}moles$
<br><br>Moles of Fe = ${{50} \over {55.85}}moles$ = Moles of H<sub>2</sub>
<br><br>No. of H<sub>2</sub> produced $= {{50} \over {55.85}}moles$<br><br>Work done $= - {P_{ext}}\,.\,\Delta V$<br><br>$= - \Delta {n_g}RT$<br><br>$= - {{50} \over {55.85}} \times 8.314 \times 298$
<br><br>= -2218.05 J
<br><br>Nearest integer = 2218
About this question
Subject: Chemistry · Chapter: Thermodynamics · Topic: Zeroth and First Law
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