Ncert Exercises & Solutions

5.6 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?

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

$2 A l + 2 N a O H + 2 H_{2} O \to 2 N a A I O_{2} + 3 H_{2}$
$2 \times 27 g 3 \times 22400 m L$

At STP (273.15K and 1 atm), 54g ( 2 x 27g ) of al gives 3 x 22400 mL of H₂

$\Rightarrow$ 0.15 g Al gives $\frac{3 \times 22400 \times 0.15}{54}$ of H₂ i.e., 186.67 mL of H₂

At STP

p₁ = 1 atm

V₁ = 186.67 mL

T₁ = 273.15 K

Let the volume of dihydrogenn be V₂ at p₂ = 0.987 atm ( since 1 bar = 0.987 atm ) and T = 20 $°$ C = (273.15 + 20) = 293.15 K.

Now,

$\frac{p_{1} V_{1}}{T_{1}} = \frac{p_{2} V_{2}}{T_{2}}$

$\Rightarrow V_{2} = \frac{p_{1} V_{1} T_{2}}{p_{2} T_{1}}$

$= \frac{1 \times 186.67 \times 293.15}{0.987 \times 273.15}$

= 202.98 mL

= 203 mL

NEET Information

courses

Company

Botany Questions

Chemistry Questions

Physics Questions

Zoology Questions