A gas bottle contains 0.250 mol of gas at 730 mm hg pressure. if the final pressure is 1.15 atm, how many moles of gas were added to the bottle?

Respuesta :

Answer: 0.049 mol



Explanation:



1) Data:


n₁ = 0.250 mol

p₁ = 730 mmHg

p₂ = 1.15 atm

n₂ - n₁ = ?


2) Assumptions:


i) ideal gas equation: pV = nRT


ii) V and T constants.


3) Solution:


i) Since the temperature and the volume must be assumed constant, you can simplify the ideal gas equation into:


pV = nRT ⇒ p/n = RT/V ⇒ p/n = constant.


ii) Then p₁ / n₁ = p₂ / n₂


⇒ n₂ = p₂ n₁ / p₁


iii) n₂ = 1.15atm × 760 mmHg/atm × 0.250 mol / 730mmHg = 0.299 mol


iv) n₂ - n₁ = 0.299 mol - 0.250 mol = 0.049 mol

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