NCERT Class XI Chemistry States of Matter Solutions

Question : 6

Total: 23

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 one bar will be released when 0.15 g of aluminium reacts?

Solution:

The reaction between aluminium and caustic soda is

2Al

2×27=54g

+ 2NaOH + 2H2O → 2NaAlO2+

3H2

3×22.4L‌at‌STP

∴ 54 g of Al produces H2 at S.T.P. = 3 × 22.4 L
0.15 g of Al will produce H2 at S.T.P. =

3×22.4

× 0.15 = 0.186 L
At STP
P1 = 1 atm
V1 = 0.186 L
T1 = 273 K
Given conditions
P2 = 1 bar = 0.987 atm
V2 = ?
T2 = 273 + 20 = 293 K
Applying ideal gas equation,

P1V1

P2V2

1×0.186

273

0.987×V2

293

⇒ V2 =

293

0.987

1×0.186

273

= 0.2030 L = 203 mL

Go to Question:

Prev Question

Next Question