A gas enters a compressor that provides a pressure ratio (exit pressure to inlet pressure equal to $\hspace{1mm} 8. \hspace{1mm}$ If a gage indicates the gas pressure at the inlet is $\hspace{1mm} 5.5 \hspace{1mm}$ psig, what is the absolute pressure, in psia, of the gas at the exit? Atmospheric pressure is $\hspace{1mm} 14.5 \hspace{1mm} lbf/in^2.$

In a cylin- der, $1.20$ mol of an ideal monatomic gas, initially at $3.60 \times 10^5 \mathrm{~Pa}$ and $300 \mathrm{~K}$, expands until its volume triples. Compute the work done by the gas if the expansion is
(d) Show each process in a $pV$-diagram. In which case is the absolute value of the work done by the gas greatest? Least?

A balloon has a mass of $0.5 \mathrm{~g}$ when completely deflated. When it is filled with an unknown gas, the mass increases to $1.7 \mathrm{~g}$. You notice on the canister of the unknown gas that it occupies a volume of $0.4478 \mathrm{~L}$ at a temperature of $50^{\circ} \mathrm{C}$. You note the temperature in the room is $25^{\circ} \mathrm{C}$. Identify the gas.

A weather balloon used by meteorologists is made of a flexible bag that allows the gas inside to freely expand. If a weather balloon containing $25.0 \mathrm{m}^{3}$ of helium gas is released from sea level, what is the volume of gas when the balloon reaches a height of 2100 m, where the pressure is $0.82 \times 10^{5} \mathrm{Pa}$? Assume that the temperature is unchanged.

A rigid, nonconducting tank with a volume of $4 m^3$ is divided into two unequal parts by a thin membrane. One side of the membrane, representing 1/3 of the tank, contains nitrogen gas at 6 bar and $100^\circ C,$ and the other side, representing 2/3 of the tank, is evacuated. The membrane ruptures and the gas fills the tank. (a) What is the final temperature of the gas? How much work is done? Is the process reversible? (b) Describe a reversible process by which the gas can be returned to its initial state. How much work is done? Assume nitrogen is an ideal gas for which $C_{P}=(7 / 2) R \text { and } C_{V}=(5 / 2) R.$

Coal can be used to generate hydrogen gas (a potential fuel) by the endothermic reaction $\mathrm{C}(s)+\mathrm{H}_{2} \mathrm{O}(g) \rightleftharpoons \mathrm{CO}(g)+\mathrm{H}_{2}(g)$ If this reaction mixture is at equilibrium, predict whether each disturbance will result in the formation of additional hydrogen gas, the formation of less hydrogen gas, or have no effect on the quantity of hydrogen gas. a. adding more C to the reaction mixture b. adding more $H_2O$ to the reaction mixture. c. raising the temperature of the reaction mixture. d. increasing the volume of the reaction mixture. e. adding a catalyst to the reaction mixture. f. adding an inert gas to the reaction mixture.

Nitrogen dioxide $\left(\mathrm{NO}_2\right)$ cannot be obtained in a pure form in the gas phase because it exists as a mixture of $\mathrm{NO}_2$ and $\mathrm{N}_2 \mathrm{O}_4$. At $25^{\circ} \mathrm{C}$ and $0.99$ bar, the density of this gas mixture is $2.7 \mathrm{~g} \mathrm{~L}^{-1}$. What is the partial pressure of each gas?

Make a sketch of the gas distribution in the plane of the Milky Way. In your sketch, map out where the molecular clouds are and draw the layer of atomic hydrogen gas that surrounds them. Then add the locations of the most prominent bubbles of hot gas. Explain why each of these components of the Milky Way’s interstellar medium is found in the location where you have drawn it.

Process Safety Progress (Dec. 2004) published a risk analysis for a natural-gas pipeline between Bolivia and Brazil. The most likely scenario for an accident would be natural-gas leakage from a hole in the pipeline. The probability that the leak ignites immediately (causing a jet fire) is .01. If the leak does not immediately ignite, it may result in the delayed ignition of a gas cloud. Given no immediate ignition, the probability of delayed ignition (causing a flash fire) is .01. If there is no delayed ignition, the gas cloud will disperse harmlessly. Suppose a leak occurs in the natural-gas pipeline. Find the probability that either a jet fire or a flash fire will occur. Illustrate with a tree diagram.

A cylinder of gas used for welding contains helium at 20 MPa (gage) and room temperature. The cylinder is knocked over, its valve is broken off, and gas escapes through a converging passage. The minimum flow diameter is 10 mm at the outlet section where the gas flow is uniform. Find (a) the mass flow rate at which gas leaves the cylinder and (b) the instantaneous acceleration of the cylinder (assume the cylinder axis is horizontal and its mass is 65 kg). Show static and stagnation states and the process path on a Ts diagram.

Car designers have been experimenting with ways to improve gas mileage for many years. An important element in this research is the way in which a car’s speed affects how quickly fuel is burned. Competitions whose objective is to drive the farthest on the smallest amount of gas have determined that low speeds and high speeds are inefficient. Designers would like to know which speed burns gas most efficiently. As an experiment, 50 identical cars are driven at different speeds and the gas mileage measured. How well does it fit?

At high pressures, a real gas does not behave as an ideal gas. For a certain range of pressures, it is suggested that for one mole of a real gas at constant temperature the relation between the pressure $p$ and volume $V$ is given by the equation $p V=A+B p \quad$ where $A$ and $B$ are constants. In an experiment, 1 mole of nitrogen gas was compressed at a constant temperature of $150 \mathrm{~K}$. The volume $V$ of the gas was measured for different values of the pressure $p$. A graph of the product $p V$ against $p$ is shown in the diagram below. a) Copy the graph and draw a line of best fit for the data points. b) Use your graph to determine the values of the constants $A$ and $B$ in the equation $p V=A+B p$ c) $p$ was measured to an accuracy of $5 \%$ and $V$ was measured to an accuracy of $2 \%$. Determine the absolute error in the value of the constant A."

Methane $\left(\mathrm{CH}_4\right)$ gas enters a horizontal, well-insulated nozzle operating at steady state at $80^{\circ} \mathrm{C}$ and a velocity of $10 \mathrm{~m} / \mathrm{s}$. Considering ideal gas behavior for the methane, determine the temperature of the gas exiting the nozzle, in ${ }^{\circ} \mathrm{C}$, if the exit velocity is $550 \mathrm{~m} / \mathrm{s}$.

Many gases can be modeled by the Ideal Gas Law, PV=nRT, which relates the temperature (T, measured in Kelvin (K)), pressure (P, measured in Pascals (Pa)), and volume (V, measured in $m^3$) of a gas. Assume that the quantity of gas in question is n=1 mole (mol). The gas constant has a value of $R=8.3 m^3$-Pa/mol-K.

Consider V to be the dependent variable and plot several level curves of the volume surface in the region $0 \leq T \leq 900$ and $0 \lt P \leq 100,000$.