`Al+3H^+ -gt Al^(3+)+ 3/2H_2` How many grams of `H_2` is formed by dissolving 900mg of Al in dilute HCl.
`Al+3H^+ rarr Al^(3+)+3/2H_2`
`Al:H_2 = 1:3/2`
molar mass of Aluminium = 27g/mol
Amount of Al added `= 0.9/27 mol = 1/30mol`
Amount of `H_2` gas produced `= 3/2xx1/30 = 1/20mol`
Molar mass of `H_2` gas = 2g/mol
Mass of `H_2 ` formed `= 2xx1/20 = 1/10g = 0.1g`
So the `H_2` gas formed are 0.1g.
There is excess HCl for the complete reaction