Ideal gases: notes and practice questions

In which of the following sets of conditions does the gas exhibit behaviour closest to an ideal gas?

A. Helium, $200\text{ kPa}$, $200\text{ K}$

B. Sulfur dioxide, $20\text{ kPa}$, $500\text{ K}$

C. Helium, $20\text{ kPa}$, $500\text{ K}$

D. Sulfur dioxide, $200\text{ kPa}$, $200\text{ K}$

A sealed container holds a fixed amount of an ideal gas. If the pressure exerted by the gas is reduced to $25\%$ of its initial value, while maintaining a constant temperature, what is the effect on the volume of the gas?

A. The volume increases by $100\%$.

B. The volume increases by $200\%$.

C. The volume increases by $300\%$.

D. The volume decreases by $75\%$.

A sample of butane, $C_4H_{10}(g)$, with a volume of $2.50 \text{ dm}^3$ is collected at $25.0 \text{ °C}$ and $100.0 \text{ kPa}$. How many moles of oxygen are needed for the complete combustion of this sample of butane?

A. $0.101$

B. $0.328$

C. $0.656$

D. $1.31$

A sealed, rigid container holds a sample of an ideal gas. Initially, the gas is at $20 \text{ } ^\circ C$ with a pressure of $P_{\text{initial}}$ kPa. The container is then moved to a warmer environment, causing the gas temperature to rise to $50 \text{ } ^\circ C$.

What is the resulting pressure in kPa?

A. Half of $P_{\text{initial}}$

B. A little less than $P_{\text{initial}}$

C. A little more than $P_{\text{initial}}$

D. Two times $P_{\text{initial}}$

A sealed reaction vessel of fixed volume contains a sample of nitrogen gas at an initial pressure of $60\ kPa$ and a temperature of $290\ K$. During a process, $1/5$ of the nitrogen molecules are removed from the vessel, and the temperature is simultaneously increased to $435\ K$.

What is the new pressure of the gas in $kPa$?

A. $18\ kPa$

B. $48\ kPa$

C. $72\ kPa$

D. $90\ kPa$