Question

0.28 g of ammonia on decomposition gave 0.25 g of nitrogen and rest
hydrogen. What will be the volume of hydrogen evolved at NTP.
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Answer 1

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Answer 2

Given info : 0.28 g of ammonia on decomposition gave 0.25 g of nitrogen and rest hydrogen.

To find : What will be the volume of hydrogen evolved at NTP ?

solution : decomposition of ammonia,

2NH₃ (g) ⇒ N₂ (g) + 3H₂ (g)

mass of Ammonia = 0.28 g

molecular weight of ammonia = 17 g/mol

so, no of moles of ammonia = 0.28/17 = 0.0165 mol

but we see,

2 moles of ammonia decomposes into one mole of nitrogen and three moles of hydrogen.

so, no of moles of hydrogen = 3/2 × 0.0165 mol

= 0.02475 mol

now volume of hydrogen gas = 22.4 × no of moles of hydrogen gas

= 22.4 × 0.02475

= 0.5544 Litre

= 554.4 ml

Therefore the volume of evolved hydrogen gas is 554.4 ml