Problem 124
Blood Pressure A typical blood pressure in a resting adult is "120 over 80," meaning 120 \(\mathrm{mmHg}\) with each beat of the heart and 80 mm Hg of pressure between heartbeats. Express these pressures in the following units: (a) torr; (b) atm; (c) bar; (d) kPa.
Problem 130
The pressure in an aerosol can is 1.2 atm at \(27^{\circ} \mathrm{C}\). The can will withstand a pressure of 3.0 atm. Will it burst if heated in a campfire to \(450^{\circ} \mathrm{C} ?\)
Problem 131
Uranus has a total atmospheric pressure of \(130 \mathrm{kPa}\) and consists of the following gases: \(83 \% \mathrm{H}_{2}, 15 \% \mathrm{He},\) and \(2 \%\) \(\mathrm{CH}_{4}\) by volume. Calculate the partial pressure of each gas in Uranus's atmosphere.
Problem 132
Derive an equation that expresses the ratio of the densities \(\left(d_{1} \text { and } d_{2}\right)\) of a gas under two different combinations of temperature and pressure: \(\left(T_{1}, P_{1}\right)\) and \(\left(T_{2}, P_{2}\right)\).
Problem 133
Denitrification in the Environment In some aquatic ecosystems, nitrate \(\left(\mathrm{NO}_{3}^{-}\right)\) is converted to nitrite \(\left(\mathrm{NO}_{2}^{-}\right),\) which then decomposes to nitrogen and water. As an example of this second reaction, consider the decomposition of ammonium nitrite: $$\mathrm{NH}_{4} \mathrm{NO}_{2}(a q) \rightarrow \mathrm{N}_{2}(g)+2 \mathrm{H}_{2} \mathrm{O}(\ell) $$ What is the change in pressure in a sealed 10.0 L. vessel due to the formation of \(\mathrm{N}_{2}\) gas when the ammonium nitrite in \(1.00 \mathrm{L}\) of \(1.0 \mathrm{M} \mathrm{NH}_{4} \mathrm{NO}_{2}\) decomposes at \(25^{\circ} \mathrm{C} ?\)
Problem 135
Using Wetlands to Treat Agricultural Waste Wetlands can play a significant role in removing fertilizer residues from rain runoff and groundwater. One way they do this is through denitrification, which converts nitrate ions to nitrogen gas: \(2 \mathrm{NO}_{3}^{-}(a q)+5 \mathrm{CO}(g)+2 \mathrm{H}^{+}(a q) \right-arrow \mathrm{N}_{2}(g)+\mathrm{H}_{2} \mathrm{O}(\ell)+5 \mathrm{CO}_{2}(g)\) Suppose \(200.0 \mathrm{g}\) of \(\mathrm{NO}_{3}^{-}\) flows into a swamp each day. a. What volume of \(\mathrm{N}_{2}\) would be produced at \(17^{\circ} \mathrm{C}\) and 1.00 atm if the denitrification process were complete? b. What volume of \(\mathrm{CO}_{2}\) would be produced? c. Suppose the gas mixture produced by the decomposition reaction is trapped in a container at \(17^{\circ} \mathrm{C} ;\) what is the density of the mixture, assuming \(P_{\text {total }}\) \(=1.00\) atm?
Problem 138
Decay Products of Uranium Minerals Radon and helium are both by-products of the radioactive decay of uranium minerals. A fresh sample of carnotite, \(\mathrm{K}_{2}\left(\mathrm{UO}_{2}\right)_{2}\left(\mathrm{VO}_{4}\right)_{2}\) \(\cdot 3 \mathrm{H}_{2} \mathrm{O},\) is put on display in a museum. Calculate the relative rates of diffusion of helium and radon under fixed conditions of pressure and temperature. Which gas diffuses more rapidly through the display case?
Problem 139
The reaction between potassium super-oxide and carbon dioxide is used to produce \(0.200 \mathrm{L}\) of \(\mathrm{O}_{2},\) which is collected over water at \(25.0^{\circ} \mathrm{C} .\) The atmospheric pressure is 750.0 torr. The vapor pressure of water at \(25.0^{\circ} \mathrm{C}\) is 24.0 torr. How many moles of \(\mathrm{O}_{2}\) have becn collected? $$4 \mathrm{KO}_{2}(s)+2 \mathrm{CO}_{2}(g) \rightarrow 2 \mathrm{K}_{2} \mathrm{CO}_{3}(s)+3 \mathrm{O}_{2}(g)$$
Problem 140
On October \(26,2014,\) Alan Eustace set a record for the highest parachute jump when he dropped from a balloon at an altitude of \(41,419 \mathrm{m},\) where the atmospheric pressure is only \(5.6 \mathrm{mmH} \mathrm{g}\) a. What is the density of air at this height? b. Is the mean free path of a gas molecule longer or shorter at this altitude than at sea level?
