Question

Both Jacques Charles and Joseph Louis Guy-Lussac were avid balloonists. In his original flight in 1783, Jacques Charles used a balloon that contained approximately 31100 L of H2. He generated the H2 using the reaction between iron and hydrochloric acid: Fe(s)+2HCl(aq)→FeCl2(aq)+H2(g)
How many kilograms of iron were needed to produce this volume of H2 if the temperature was 21 ∘C? (For simplicity, assume that the pressure experienced by the balloon will be 1.00 atm.)

Answer 1

Answer:

$m_{Fe}=71.982 kg$

Explanation:

First of all, we need  to calculate the moles of H2. Assuming the H2 is an ideal gas:

$n=\frac{P*V}{T*R}$

$n=\frac{1atm*31100L}{294K*0.082 L*atm*mol^{-1}*K^{-1}}$

$n=1290 mol$

Now, to produce 1 mol of H2 is required 1 mol of Fe:

$m_{Fe}=n*M=1290mol*\{55.8 g}{mol}$

$m_{Fe}=71982 g=71.982 kg$