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

Question

The drain cleaner, Drainex contains small bits of aluminium which react with caustic soda to produce dihydrogen. What volume of dihydrogen in mL at 20 ° C and one bar will be released when 0.15 g of aluminium reacts? (Take 1 bar = 0 .987 atm )

TestHub · Accepted Answer

The reaction between aluminium and caustic soda is
$\underset{\underset{= 54 g}{2 \times 27}}{2 A l} + 2 N a O H + 2 H_{2} O \to 2 N a A l O_{2} + \underset{\underset{atSTP}{3 \times 22.4 L}}{3 H_{2}}$
So 54 g of Al produces $H_{2}$ at STP $= 3 \times 22.4$ L
0.15 g of Al will produce $H_{2}$ at STP
$= \frac{3 \times 22.4}{54} \times 0.15$
$= 0.186 L$

At STP	Given Conditions
$P_{1} = 1$ atm	$P_{2} = 1$ bar $= 0.987$ atm
$V_{1} = 0.186$ L	$V_{2} = ?$
$T_{1} = 273$ K	$T_{2} = 273 + 20 = 293 K$

Applying ideal gas equation, $\frac{P_{1} V_{1}}{T_{1}} = \frac{P_{2} V_{2}}{T_{2}}$
$\frac{1 \times 0.1867}{273} = \frac{0.987 \times V_{2}}{293}$
$V_{2} = \frac{293}{0.987} \times \frac{1 \times 0.1867}{273}$
$= 0.2030$ L $= 203$ mL

Chemistry - Ideal Gas Question with Solution | TestHub

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