Question

The volume of certain gas was found 560cm3, when pressure was 600mm of Hg. If the pressure decreases by 4 %. Find the new volume of gas. the temperature is kept constant.

Answer 1

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✤ Required Answer:

✒ GiveN:

• Initial volume of gas = 560 cm³
• Initial pressure of the gas = 600 mm of Hg
• Pressure decreases by 4 %
• Temperature is constant

✒ To FinD:

• Final volume of the gas.....?

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✤ How to solve?

In the question, it is given that Temperature is constant and pressure & Volume are varying accordingly. So, Here we will apply the gas laws which is the interrelationship between the measurable quantities:

☃️ There are several gas laws, But according to conditions given, we will use only Boyle's law.

Boyle's law:

The product of pressure and volume of a given mass at constant temperature is constant. Or, Volume is indirectly proportionate to the pressure of gas.

$\large{ \boxed{ \sf{P_1V_1 = P_2V_2}}}$

( T = constant)

So, Let's solve the question by using Boyle's law...

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✤ Solution:

We have,

• Initial volume = 560 cm³
• Initial pressure = 600 mm of Hg
• Final pressure = 4% less than Initial pressure.

Finding the final pressure,

➝ Final pressure = (100 - 4/100)Initial pressure

➝ Final pressure = (100 - 4/100)600 mm of Hg

➝ Final pressure = 96/100 × 600 mm of Hg

➝ Final pressure = 96 × 6 mm of Hg

➝ Final pressure = 576 mm of Hg

⚘ Now, finding the Final volume of gas,

By using Boyle's law,

➝ P1V1 = P2V2

➝ 600 × 560 = 576 × V2

➝ V2 = 600 × 560 / 576

➝ V2 = 25/24 × 560

➝ V2 = 583.34 cm³ (approx.)

☀️ Final volume of the gas = 583.34 cm³

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