Question

The drain cleaner, Drainex contains small bits of aluminium which react with caustic soda to produce dihydrogen. What volume of dihydrogen at 20°C and 1 bar will be released when 0.15 g of aluminium reacts?

Answer 1

"Aluminium" reacts with "caustic soda" in accordance with the "reaction".

The reaction of aluminium with caustic soda can be represented as follows

$\begin{matrix} 2Al \\ \left( 2\quad \times \quad 27 \right) g \end{matrix}\quad +\quad 2NaOH\quad +\quad 2{ H }_{ 2 }O\quad \longrightarrow \begin{matrix} 2NaAl{ O }_{ 2 } \\ \left( 3\quad \times \quad 22400 \right) ml \end{matrix}\quad +\quad 3{ H }_{ 2 }$

Therefore, volume of hydrogen at STP released

When 0.15 g of Al reacts

$V\quad =\quad \frac { 0.15\quad \times \quad 3\quad \times \quad 22.4 }{ 54 } \quad =\quad 187\quad ml$

From given

${ P }_{ 1 }$= 1 bar

${ P }_{ 2 }$= 1 bar

${ T }_{ 1 }$ = 273 K

${ T }_{ 2 }$ = 20 + 273 = 293 K

$V_{ 1 }$= 187 ml  

${ V }_{ 2 }$= ?

When pressure is held constant, then $V_{ 2 }\quad =\quad \frac { { P }_{ 1 }{ V }_{ 1 }{ T }_{ 2 } }{ { P }_{ 2 }{ T }_{ 1 } }$

Or

${ V }_{ 2 }\quad =\quad \frac { 1\quad \times \quad 187\quad \times \quad 293 }{ 0.987\quad \times \quad 273 } \quad =\quad 201\quad ml$

Therefore, 201 ml of dihydrogen will be formed."

Answer 2

Explanation:

The drain cleaner, Drainex contains small bits of aluminum which react with caustic soda to produce dihydrogen. What volume of dihydrogen at 20 °C and one bar will be released when 0.15g of aluminum reacts? Therefore, 201 mL of dihydrogen will be released.