Some Basic Concepts Of Chemistry Question 189
Question: What volume of $ NH _3 $ gas at STP would be needed to prepare 100ml of 2.5 molal (2.5m) ammonium hydroxide solution
Options:
A) 0.056 litres
B) 0.56 litres
C) 5.6 litres
D) 11.2 litres
Show Answer
Answer:
Correct Answer: C
Solution:
2.5 molal $ NH _4OH $ means 2.5 moles of $ NH _3 $ in 1000g $ H _2O $ (1000cc of solution) Hence, 100cc solution of $ NH _3 $ requires = 0.25 mole $ =0.25\times 22.4L=5.6L $ .