The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce hydrogen. What volume of hydrogen at 20 degree Celsius and one bar will be released when 0.15g of aluminum reacts?

Therefore volume of hydrogen at STP released when 0.15g of Al reacts

V_{1} =0.15 x 3 x 22.4 /54 = 187ml

Now P1 = 1 bar,

P_{2} = 1 bar

T_{1} = 273 K

T_{2} = 20 + 273 = 293 K

V_{1} = 187 ml

V_{2} = x

When pressure is held constant, then

V_{2} = P_{1} V_{1} T_{2} / P_{2} T_{1}

OR

x = 1 × 187 × 293 **/** 0.987 × 273

= 201 ml

Therefore, 201 mL of dihydrogen will be released.