Question #272417
A company uses Ha gas to generate electricity. They studied a smaller scale model reaction to figure out the maximum amount of H2 gas that they can produce. For this purpose, they used an alloy consisting of 95% Al by mass. The alloy has a density of 3.12 g/cm and they took a 0.875 cm small piece of alloy to react with 200 mL of 1.2 M solution of HCI based on the given Al specific reaction. What is the maximum amount of Ha: gas that can be produced? What are the limiting and remaining reagents ? How can they increase the amount of Ha gas that they obtained? AlHCI AICls H2 (not balanced)
Expert's answer
On way of working this type of problem is to assume that one starts with an alloy mass of 1 kg = 1000 g.
Then there would be 0.70 x 1000 = 700 g oif Al and .30 x 1000 = 300 g Mg.
Since the Molar Mass of Al is 26.982 g /mole , there are 700/ 26.982 = 25.94 molles of Al, similarly there are
300 / 24.303 = 12.34 moles of Mg (Molar mass of Mg is 24.305)
Thus the mole fraction of Al ( f Al ) is 25.94/(25.94 + 12.34) = 0.6776
and the mole fraction of Mg (f Mg ) is 12.34 /(25.98 + 12.34) = 0.3224
The density of alloy will then be 0.6776 x 2700 + 0.3324 x 1740 = 2390 kg / m^3
