To understand what is assumed to be constant when using the combined gas law, let's examine the principles of gas laws and how they relate to the combined gas law.
1. Boyle's Law:
[tex]\[
P_1 V_1 = P_2 V_2
\][/tex]
- Variables: Pressure (P) and Volume (V)
- Constants: Temperature (T) and Moles of gas (n)
2. Charles's Law:
[tex]\[
\frac{V_1}{T_1} = \frac{V_2}{T_2}
\][/tex]
- Variables: Volume (V) and Temperature (T)
- Constants: Pressure (P) and Moles of gas (n)
3. Gay-Lussac's Law:
[tex]\[
\frac{P_1}{T_1} = \frac{P_2}{T_2}
\][/tex]
- Variables: Pressure (P) and Temperature (T)
- Constants: Volume (V) and Moles of gas (n)
4. Combined Gas Law:
[tex]\[
\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}
\][/tex]
- Variables: Pressure (P), Volume (V), and Temperature (T)
- Constants: Moles of gas (n)
The combined gas law incorporates the relationships described by Boyle’s, Charles’s, and Gay-Lussac’s laws. It considers that the product of pressure and volume, divided by temperature, is constant, provided the amount of gas (in moles) is held constant.
Therefore, based on the information provided, volume and moles of gas are the constants for Gay-Lussac’s law, while moles of gas are the constants when using the combined gas law.
So, the answer to the question "What is assumed to be constant when using the combined gas law?" is:
Volume and moles of gas
