Name & Variables & Constants & Equation Boyle's law & pressure, volume & ? & P_(1) V_(1)-P_(2) V_(2) Charles's law & volume, temperature & ? & (V_(1))/(T_(1))-(V_(2))/(T_(2)) ? & temperature, pressure & volume, moles of gas ? & pressure, temperature, volume & ? & (P_(1) V_(1))/(T_(1))-(P_(2) V_(2))/(T_(2)) What is assumed to be constant when using the combined gas law? pressure number of moles volume and moles of gas pressure and temperature

## Step 1: Identify the combined gas law<br />### The combined gas law is derived from Boyle's Law, Charles's Law, and Gay-Lussac's Law. It combines these three laws into one equation: <br />\[<br />\frac{P_1 V_1}{T_1} = \frac{P_2 V_2}{T_2}<br />\]<br />where $P$ is pressure, $V$ is volume, and $T$ is temperature.<br /><br />## Step 2: Determine the constant in the combined gas law<br />### In the combined gas law, the number of moles of gas remains constant. This is because the combined gas law assumes a closed system where no gas is added or removed.