6 Gases and the Gas Laws Free Online FlashCards

What causes gas pressure, and how is pressure defined?

Gas particles collide with container walls, exerting force over an area. Pressure is force per unit area.

How are atmospheres, kilopascals, and torr related?

The equivalent pressures are $1\ \mathrm{atm}=101.325\ \mathrm{kPa}=760\ \mathrm{torr}$.

How do you convert Celsius temperature for gas-law calculations?

Convert Celsius to kelvins using $T(\mathrm{K})=T(^{\circ}\mathrm{C})+273.15$. Gas-law temperatures must be in kelvins.

What relationship does Boyle’s law describe?

At constant temperature and amount, pressure and volume vary inversely: $P_1V_1=P_2V_2$.

What relationship does Charles’s law describe?

At constant pressure and amount, volume is proportional to absolute temperature: $\frac{V_1}{T_1}=\frac{V_2}{T_2}$.

What relationship does Amontons’s law describe?

At constant volume and amount, pressure is proportional to absolute temperature: $\frac{P_1}{T_1}=\frac{P_2}{T_2}$.

What relationship does Avogadro’s law describe?

At constant pressure and temperature, volume is proportional to the amount of gas: $\frac{V_1}{n_1}=\frac{V_2}{n_2}$.

Which equation relates changing pressure, volume, and temperature for a fixed gas amount?

For a fixed amount of gas when pressure, volume, and temperature change, use $\frac{P_1V_1}{T_1}=\frac{P_2V_2}{T_2}$.

What is the ideal gas equation, and how should you choose $R$?

The ideal gas equation is $PV=nRT$. Choose $R=0.08206\ \mathrm{L\cdot atm\cdot mol^{-1}\cdot K^{-1}}$ or $R=8.314\ \mathrm{kPa\cdot L\cdot mol^{-1}\cdot K^{-1}}$ to match the units.

When is the ideal-gas model especially useful?

The ideal-gas model is a useful approximation for many gases, especially at relatively low pressure and high temperature.

What does Dalton’s law state about a nonreacting gas mixture?

For a mixture of nonreacting gases, total pressure is the sum of their partial pressures: $P_{\text{total}}=P_1+P_2+\cdots$.

How do mole fraction and total pressure determine a component’s partial pressure?

A component’s mole fraction is $X_i=\frac{n_i}{n_{\text{total}}}$, and its partial pressure is $P_i=X_iP_{\text{total}}$.