Which is the correct equation for Gay-Lussac’s Law?

The correct equation for Gay-Lussac’s Law is P1/T1 = P2/T2.

Here's a step-by-step explanation:

1. Gay-Lussac's Law states that the pressure of a gas is directly proportional to its absolute temperature, provided its volume is kept constant.

2. This can be mathematically expressed as P ∝ T, where P is the pressure of the gas, T is its absolute temperature, and ∝ denotes 'is proportional to'.

3. To convert this proportionality into an equation, we introduce a constant of proportionality. However, in this case, the constant is 1 (assuming the amount of gas and the volume remain constant), so the equation becomes P = kT, where k is the constant of proportionality.

4. If we consider two states of the gas (state 1 and state 2), each with its own pressure and temperature (P1, T1 and P2, T2 respectively), the equation can be written for each state as P1 = kT1 and P2 = kT2.

5. Since the constant k is the same in both equations, we can set them equal to each other, giving us P1/T1 = P2/T2.

So, the correct equation for Gay-Lussac’s Law is P1/T1 = P2/T2.