question_answer 1)

The drain cleaner, 'Drainex contains small bits of aluminium which reacts with caustic soda to produce dihydrogen. What volume of hydrogen at \[20{}^\circ C\]and one bar will be released when 0.15 g of aluminium reacts?

Answer:

The reaction involved is: \[\underset{2mol\,or\,54g}{\mathop{2Al+}}\,2NaOH+2{{H}_{2}}O\to 2NaAl{{O}_{2}}+\underset{3mol}{\mathop{3{{H}_{2}}}}\,\] Number of moles of H^ produced = \[\frac{3}{54}\times 0.15\] \[=8333\times {{10}^{-3}}\] \[PV=nRT\] \[1\times V=8.33\times {{10}^{-3}}\times 0.083\times 293\] \[V=0.202litre\] \[=202mL.\]