Question
Question: Equation of Boyle’s law: A) \(dP/P = - dV/V\) B) \(dP/P = + dV/V\) C) \({d^2}P/P = - dV/V\) ...
Equation of Boyle’s law:
A) dP/P=−dV/V
B) dP/P=+dV/V
C) d2P/P=−dV/V
D) d2P/P=+dV/V
Solution
Hint : Boyle’s law is also known as the pressure-volume relationship which states that when the temperature is constant the pressure of a fixed amount of gas varies inversely with its volume.
_Complete step by step solution : _
-We should first start by seeing what Boyle’s law is: Boyle’s law is an experimental gas law that describes the relationship between pressure and volume when the temperature is constant. It states that pressure of a gas tends to increase when the volume of a container decreases.
It can be written as: Pα1/V (Temperature is constant)
P=k(1/V)
PV=k
where k is proportionality constant whose value depends on the temperature of the gas, amount of gas and units of P and V.
So, for a gas at temperature T, occupying volume V1 at pressure P1 and volume V2 at pressure P2, Boyle’s law can be written as:
P1V1=P2V2=k
P1/P2=V2/V1
-Now, we use the equation: PV=k, to derive the differentiated form of Boyle’s Law. Differentiate the equation: PV=k .
By differentiating it we get: dP/P+dV/V=0
So, dP/P=−dV/V
So, the correct option is, (A) dP/P=−dV/V
Note : The Boyle’s law formula: P1/P2=V2/V1; is valid for only a gas at a constant temperature but varying pressure and temperature and not for 2 different gases.