Answer:0.119g
Explanation:equation of rxn is
2Al+6HCl=2AlCl3+3H2
From ideal gas eqn
PV=nRT
n=PV/RT
P here is the partial pressure of H2 from the qtn.According to Dalton law of partial pressure, PT=PH2+PH20
PT=0.89atm given
PH20=25.2mmhg given=25.2/760atm,=0.033atm
PH2=PT-PH20
PH2=0.89-0.033=0.857atm
T=26+273=299K
R=0.082atmdm^-3mol^-1K^-1
V=190.6ml=190.6cm3=190.6/1000=0.1906dm3
n=PV/RT
n=0.857*0.1906/0.082*299
=0.00667moles of H2.
From the eqn of reaction,
2moles of Al reacts to gv 3moles of H2
xmoles of Al will give 0.00667moles of H2
xmoles=0.00667*2/3 (cross multiplying)=0.00444moles of Al
From the relationship, n=mass/MW
mass=MW*n
MW of Al=27g/mol
mass=0.0044moles*27g/moles
mass=0.119grams of Al.