To determine which of the given equations represents the combined gas law, we need to understand the combined gas law itself.
The combined gas law expresses the relationship between pressure (P), volume (V), and temperature (T) of a fixed amount of gas. The formula is:
[tex]\[
\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}
\][/tex]
Let's examine each of the given choices:
- A) P₁ = P22
This equation indicates that pressure P₁ is equal to P times 22, which doesn't relate to volume or temperature at all. Thus, it does not represent the combined gas law.
- B) P₁₁ = 22
This notation is unclear and not readable. It does not relate pressure, volume, and temperature coherently. Hence, it can't be the correct representation of the combined gas law.
- C) P1T1 = P22
This equation implies that the product of the initial pressure (P1) and initial temperature (T1) is equal to P times 22. This does not incorporate volume and does not match the structure of the combined gas law.
- D) P₁V₁/T₁ = P₂V₂/T₂
This choice precisely matches the structure of the combined gas law:
[tex]\[
\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}
\][/tex]
It includes both pressures, both volumes, and both temperatures correctly related.
Therefore, the correct choice is:
D
