Which has more atoms: 1 kg of iron or 1 kg of aluminum? S/gy5 x h(,pjxaee the periodic table ory 5apx( xh,/jg Appendix B.

Name several properties of materials that coulekprz- f/v.i9d be exploited to make a thermometerz-r/ vke.pi f9.

Which is larger, 1 Cz zsm h:o,4c1uq1aj-r $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is fw*qp74 -rplq0a0 bpc*) ryxhnot in thermal equilibrium with system C, what can you say about the temperat*0hw) qpybplx- *carfq47pr 0ures of A, B, and C?

A flat bimetallic strip consists of alsm.(76ckul ek chb7 ,kuminum riveted to a strip of iron. When heated, the str m.kh7(ks6lce ubck ,7ip will bend. Which metal will be on the outside of the curve? [Hint: See Table 13–1.] Why?

In the relation $\Delta$L = $\alpha$ $L_0$ $\Delta$T, should $L_0$ be the initial length, the final length, or does it matter? Explain.

The units for the coefva rk4nhz: 4 :6of8qfhficient of linear expansion $\alpha$ are $(C?)^{-1}$ and there is no mention of a length unit such as meters. Would the expansion coefficient change if we used feet or millimeters instead of meters? Explain.

Figure 13–27 shows a diagram of a simplf8- ,n.jqtk7 qnwuuf,e thermostat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wifjn-, tu8.,nk7q wuf qres. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixp ;qcr3zq) z4eed at the ends often have a section in the shape of a U. Wh 4zqerp3q );czy?

A flat, uniform cylinder of lead floats in mercury at 6wa60y.m.zzdw d b/h0hagzs7 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glass thermometer is first placed *kxlr tp. 56fnboad- 3c+8vc tin a hot tub of water, the mercury ini3rpn *ld8bt cf.ckatx+ o 6-5vtially descends a bit and then rises. Explain.

A glass container may break if one part ofn i.vs2 lze67/4 p d.u8hnmtpk it is heated or cooled more rapidly than adjacent parts. Explaipm6ptnl.inv.7k es/hd84z u 2 n.

The principal virtue of Pyrex glass is that its coeffi8x(7,ytld kcez bw92x cient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat z,cwkb7(x xt9ey 8ld2resistance of Pyrex.

Will a grandfather clock,fr uth.d8ym- / accurate at 20 $^{\circ} $ C, run fast or slow on a hot day (30 $^{\circ} $ C)? Explain. The clock uses a pendulum supported on a long, thin brass rod.

Freezing a can of soda will cause its bottom and tq; ahs1d8lk3 dd pas+me 474icop to bulge so badly the can will not sdd8l ssa eqch7aim 4+413; dpktand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its thgjb bl:)ttb2vl :o89vbn;5q 4g8zji emperature increases. When a gas expands against a piston, it cools. Explain these changes in temperature using th z 24nojl)t5;gl:9vvb 8qbbi:b 8g thje kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum c;zh:ggthw,-s;r+,)fdf3uh id uk j1sphere submerged in water increase or decrease if the temperature is incf;;cd -:fg 1+srhuhu,gk ) iz3, tjdhwreased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and--6b ccb m,qxr the relation between average kinetic energy and the absolute tec-qr ,c6b- mbxmperature.

Explain in words how Gay-Lussac’s law follows from kinetic theorv 7 gav5u5m9b9y+ivcnou). mby.

As you go higher in the Enm+c f :o*ri:u ha 8wszp+.w*farth’s atmosphere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must hl431p yw-u+q3ey jyan ave to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Earale- 33yqwujn+ 41pyy th due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates m8r 3uhtr c(idovy ok2o t;ae.8hob;05ore quickly than water at room temperature. What can you infer about the molecular properties of one rela ytoua2rthdk .8r;0h ;5vb3 o(i8ooective to the other?

Explain why a hot humid day is far more uncomfortable than a hot dr iqwxy:k2l t))y day at the same yi wkq)t:)l2 xtemperature.

Is it possible to boik*oh*(w qy)z fl water at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same q.p m ,4-o1 zaeq;clambut the humidity is different. Which is more dense, the dry air or the humid air at the same T? Explain.4 1oacqz -m.l,aep;m q

Explain why it is dangerous to open the radiator uom/:4i h ,yd.caw 3ghcap of an overheated automobile engin,c.yhwgm 4 a:uiod /3he.

Why does exhaled air appear as a lcm.z6nt) m/y,vjb3 jfittle white cloud in the winter (Fig. 13–28)?

  How many atoms are there in(lsxmr4 u:2wg a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare tow kghc*x6ahir/ 65aqo0/dx p9 the number in a sicx*hxq96g d56kha /iwap0r/olver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is of0cxq5f5yr jx0 ten taken to be 68°F. What is this on the Celsius scale?f00qyxr 5 jcx5   $^{\circ} $ C
(b) The temperature of the filament in a lightbulb is about 1800 $^{\circ} $ C. What is this on the Fahrenheit scale?    $^{\circ} $ F

  Among the highest and lowdmqw -qtlx42q5 mmymv a *b:,6n w7hr6est temperatures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

  (a) 15 $^{\circ} $ below zero on the Celsius scale is what Fahrenheit temperature?    $^{\circ} $ F
(b) 15 $^{\circ} $ below zero on the Fahrenheit scale is what Celsius temperature?   $^{\circ} $ C

  In an alcohol-in-glass thermometer,yr2 trdv 5y uoco445,p the alcohol column has length 11.82 cm at 0.0c yo4t5p r5ru ,42voyd $^{\circ} $ C and length 22.85 cm at 100.0 $^{\circ} $ C. What is the temperature if the column has length
(a) 16.70 cm,    $^{\circ} $ C
(b) 20.50 cm?    $^{\circ} $ C

  A concrete highway is built of slabs 12 m long (20 pw784d cv ornx87a1yx $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

  Super Inva$^{TM}$, an alloy of iron and nickel, is a strong material with a very low coefficient of linear expansion [0.2$ \times10^{ -6}$(C?)$^{-1}$]
A 2.0-m-long tabletop made of this alloy is used for sensitive laser measurements where extremely high tolerances are required. How much will this table expand along its length if the temperature increases 5.0 $^{\circ} $ C? Compare to tabletops made of steel.   $ \times10^{-6 }$ m    $ \times10^{-4 }$ m

  The Eiffel Tower (Fig. 13–29) is built of wrought ir9k5 w :p,zdzot2p yww xsfg2(2on approximately 300 m tall. Estimateftzyw d29: gkw ws2op,2x5(pz how much its height changes between July (average temperature of 25°C) and January (average temperature of 2 $^{\circ} $ C). Ignore the angles of the iron beams, and treat the tower as a vertical beam.    m

  To make a secure fit, rivetcs thk f:2506j :mwdjps that are larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter aj s f0d 6t5:wm:2jkcpht 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water at 4oi v vrp ohi.g4h(o.,vs1* dr* $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its chd2 d c ca-*kxr1bghg7- p3wod4ange in volume if it is heate- pb3a c*wddhg-dckro 124g7xd from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to thezyl; l5zibvs)+zd 89p brim with 350.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of(hge e-b4 )epn water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be placed in a ring gw i7p2mpz2v.b6j mv;made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, f4qi z .d k 8-vdy*qa;m.ew(yanarrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the coefficient of vol q e* d -yiakam4wyq.(8f.;dzvume expansion $\beta$.

(a) Show that the cha,*fnlryf 2/vcjd6 tiza-5h4p nge in the density $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular plate of length l and width w haswrgd9b(62a e x nhtyq98w6ex7 coefficient of linear expansion h27agnx96 x w6e9yw e8bq(rtd$\alpha$ Show that, if we neglect very small quantities, the change in area of the plate due to a temperature change $\Delta$T is $\Delta$A = 2$\alpha l w$$\Delta$T See Fig. 13–30.

Show that for an isotropic pzb(lb.;a8a c solid, $\beta$ = 3$\alpha$ if the amount of expansion is small. $\beta$ and $\alpha$ are the coefficients of volume and linear expansion, respectively. [Hint: Consider a cubical solid, and neglect very small quantities. See also Problem 18 and Fig. 13–30.]

  The pendulum in a grandfather clock is madkjch470 61 fgjqkbd8ee of brass and keeps perfect time at 17ekdh7 bfg1kj 86qc 4j0 $^{\circ} $ C. How much time is gained or lost in a year if the clock is kept at 25 $^{\circ} $ C? (Assume the frequency dependence on length for a simple pendulum applies.)$\approx$    min(Round to the nearest integer)

  (a) The tube of a mercury thermometer has an inside diameter of 0.140 msvd 4fq07-5 ytw ed(7q6ei ybgkzw(4x m. The bulb has a volume of 0.2bk(w 4esy7wev6 qg- 0 y7di(5qxtfdz455 $cm^3$ How far will the thread of mercury move when the temperature changes from 11.5 $^{\circ} $ C to 33.0 $^{\circ} $ C? Take into account expansion of the Pyrex glass.    cm(b) Determine a formula for the length of the mercury column in terms of relevant variables. Ignore tube volume compared to bulb volume.

  A 23.4-kg solid aluminum cylindosewc:j( p3 )iun: ai+rical wheel of radius 0.41 m is rotating about its axle on frictionless bearings with angai+pus 3njwo e)c(i::ular velocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired length when at2gq.j7.m uplj dr-69qoq 5q9m9 uwuvj 15°C. How much stress is required to keep it at this length if the temperaturew or9gqju2 6ud qmu5qq . mpvl.9jj-79 increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel)c ,c qxl+/ikhzo7nwwd+r a3 ( I-beam of cross-sectional area 0.041$m^2$ is rigidly connected to two vertical steel girders. If the beam was installed when the temperature was 30$^{\circ} $ C, what stress is developed in the beam when the temperature drops to -30 $^{\circ} $ C (b) Is the ultimate strength of the steel exceeded? (c) What stress is developed if the beam is concrete and has a cross-sectional area of 0.13$m^2$ Will it fracture?

  A barrel of diameter 1il07k5fb q.2 i kjs,;abioh 0o34.122 cm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the K)tx4o;npzjk9 txt- r6 elvin scale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fahrenheit scalewiqxv,bt ;l86 ?    $^{\circ} $ F

  Typical temperatures in the interior of the Ei(5g gq //rq )vdrpsv/arth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

  If 3 $m^2$ of a gas initially at STP is placed under a pressure of 3.20 atm, the temperature of the gas rises to 38.0$^{\circ} $ C. What is the volume?    $m^3$

  In an internal combustion eng;(cbdgdl :66xv c*hoc ine, air at atmospheric pressure and a temperature ofx 6(*ovcdc hl6:; gbcd about 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP using the ideal gas lvsm ,r(6 thscwm89+ ymaw.    kg/$m^3$

  A storage tank contains y /xl2dpq h.wg-68x y/rz w9di21.6 kg of nitrogen ($N_2$) at an absolute pressure of 3.65 atm. What will the pressure be if the nitrogen is replaced by an equal mass of $CO_2$    atm

  A storage tank at STP cogz+1: g;ezat 93zvxuqyg(:djx,k oj)ntains 18.5 kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gas is at 10 q+qr6i0; hbrc.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L container holding 105.0 kg of argon g4rb /ait (l.klas at 385 K?l.rlki a/ t4b(   $ \times10^{ 8}$Pa

  A tank contains 26.0 3xigy9ettg .wz*x/s7 kg of $O_2$ gas at a gauge pressure of 8.70 atm. If the oxygen is replaced by helium, how many kilograms of the latter will be needed to produce a gauge pressure of 7.00 atm?    kg He

  A hot-air balloon achieves its buoyant lift by heating the air-lffzk.wk3 fkhtv*,r f)t noz(6+:lu inside the balloon, which makes it less dl: tfkt ulo+ nzz)wvkf-*h fr.6fk,3(ense than the air outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air at 1l +s,9zpy6pp:in r jw,5 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen :z(i*jv4+f t rhb:o4 osar 40i6xvhzoat 18.0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at sea level and v*z 3klh rl;3zwvn/5q 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the number pm;qv8 tom:w4of molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? Ho6(/b y1ep(w m2jkzoxtw many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number oervdjb1zr;xu;o65g2 f (a) moles,    $ \times10^{22 }$ moles and (b) molecules of water in all the Earth’s oceans. Assume water covers 75% of the Earth to an average depth of 3 km. $\approx$    $ \times10^{46 }$ molecules

  A cubic box of volumo zc30 (ctb-w 8pf,kgje 5.1$ \times10^{ -2}m^3$ is filled with air at atmospheric pressure at 20 $^{\circ} $ C. The box is closed and heated to 180 $^{\circ} $ C. What is the net force on each side of the box?    N

  Estimate how many molecules of air are in each 2.0-L bz x3lfx07u8cv 7 c/wtureath you inhale that were also in7 3zxuwc8l f/utvc0x7 the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen molecule ax+zmy5frh 725s(zqfi t STPix2zh ( 55sq r7ffz+ym?    $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C?   $ \times10^{3 }$ J

  Calculate the rms speed of helium atoms nk7rcl cloa 3f(m34b*near the surface of the Sun at a temperaturb(73 fl*ak3clorm4n c e of about 6000 K.    m/s

  By what factor will the rms speed of gas molecules ;6)ft;lta j ceglq9x+ygc39yincrease if the temperature is ice y9y; j)+ x t;6a9gf3cltqglncreased from 0 $^{\circ} $ C to 100 $^{\circ} $ C?   

  A gas is at 20 $^{\circ} $ C. To what temperature must it be raised to double the rms speed of its molecules?    $^{\circ} $ C

  Twelve molecules have the following sd m9u..v)jskc0sc( jb peeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rms spem( u.0dj.s9s vk )cjbced. $v_{rms}$ =    km/s

  The rms speed of molecules in a lldqr5q 6( 5vt/:rvzfgas at 20.0 $^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a gas is doubled while its volume is held constant,xpm 6ima8b+h-s6sr. .xqz* j s by what factor mq86bm s zjx *+s-hxa.rsi.6pdoes $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is girn5 l xx2uij04eudn(; ven by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases at the same t-yq gg; w8;ddhemperature, the ratio of their rms speeds is equal to the inverse ratio of the square rootsy;g8 ;q-hwg dd of their molecular masses.

  What is the rms speed of niktlafr5 pv- 5v/(g ;hwtrogen molecules contained in an 8.5$-m^3$ volume at 2.1 atm if the total amount of nitrogen is 1300 mol?    m/s

  Calculate (a) the rms speed of a d6ql8 lk4dfa:q4 y-rfn oxygen molecule at 0 $^{\circ} $ C    m/s
(b) determine how many times per second it would move back and forth across a 7.0-m-long room on the average, assuming it made very few collisions with other molecules.    round trips per sec

  What is the average distance between nitrogen moleculeaiw-1 hop(p3mmi:s3 fs at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecula:3)3 pbeqirk. z)oqyp r mass is 89 u in a living cell at kiyq:3p obpe)q z .r)337 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a gf za ;l u btwv8k94;flhfq1e7*as can be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uranium, bdru d2f,9m b:$^{235}$U and $^{238}$U (the superscripts refer to their atomic mass), can be separated by a gas-diffusion process by combining them with fluorine to make the gaseous compound UF$_6$ Calculate the ratio of the rms speeds of these molecules for the two isotopes, at constant T.   

(a) At atmospheric pressure, in wha)qce* dy hn6mtp0x*8u t phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when thel2r-gixc 7o,7 g ih:yd pressure is 0.01 atm and the temperature is (a) 90hcgorg7i2: lyd7-i ,x $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (appr ;imp.k +vzj..i84m 6 xhkne6d8pdtpsoximately) if the humidity is 50% on a day when the temperature 8d6m j6.mpspx h. .4 dinketp+ikz8v;is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressuw pxx 1.(8/pg3c gtm:o reemv5re at a place where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular plack27/) ix e 4kevjojwiak3 +ef-e in the mountains is 0.72 atm, estimate the temperature awv/fe j) ke2ik +kx473ij-eoat which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 530 Paz nx-ct(2 gir5 and52zi(gt-cr xn the relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pre5z7:s7w/o x/e ct+u ,z t;7ib judgfpsssure of water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker ifu4u, m/r5dvhc- 0ycf h the water is boiling a0hr-fm,uu cv5 cy4/dh t a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of volume 68ma djz +78k .2 t0(w7;yuk5rwdgmvjnu0$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its deeo kmc192ep1g 63r+ gs o5wbqhw point of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycinenkj.z,5aq 2 wcel 8()t d2hvfn molecule (see Table 13–4) to diffuse a disndw,jc( t85a)2vlz 2f nqkhe.tance of 15 $\mu m$ in water at 20$^{\circ} $ C if its concentration varies over that distance from 1 mol/$m^3$ to 0.4 mol/$m^3$ Compare this “speed” to its rms (thermal) speed. The molecular mass of glycine is about 75 u. t $\approx$    s ([color=rgba(0, 0, 0, 0.85)]Round to one decimal places) $v_{diffuse}$    $ \times10^{ -5}$ m/s
$v_{rms}$    m/s

  Oxygen diffuses from the surface of insects to the inkyk7aic ,ph;+ a+aq* bterior through tiny tubes called tracheae. An average trachea is about 2 mm long and has cross-sectional hb +*q7kkypa,+ ai;a carea of $ 2\times10^{-9 } m^2$ Assuming the concentration of oxygen inside is half what it is outside in the atmosphere,
(a) show that the concentration of oxygen in the air (assume 21% is oxygen) at 20$^{\circ} $ C is about 8.7 mol/$m^3$ then $\approx$    mol/$m^3$(Round to one decimal places)
(b) calculate the diffusion rate J,    $ \times10^{-11 }$ mol/s
(c) estimate the average time for a molecule to diffuse in. Assume the diffusion constant is $ 1\times10^{-5 } m^2/s$    s

  A precise steel tape measure haihd5 go,dn 8aa)wzkw.84ld a1s been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has been calib4- jj6n)l xky-q zb:7gj qy:hyrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A Pyrex measuring cup was calibrated at normal 6 ynd82bsx 8ikroom temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup are d8si68y b kn2xhot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helium gas cylinder is initially 28 a (f f7wa)y.(fza94z lasib/+h7yqbs xtm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction oszb fyb/ffwazq77i+lh xy (a) (94s .af the original gas remains in the cylinder?   

  Estimate the number of air s +1 . m :nnjs61kghsgtex1j2 ,lj a3l8mj7fidmolecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m. Assume the temperaturegn6j13gs d.xj21 e h1nj8am+tis 7lskl: , fjm is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about one atom per3 x. sgdp:6:yu qm23x3s mrura $cm^3$ mainly hydrogen atoms, and the temperature is about 2.7 K. Calculate the rms speed of these hydrogen atoms, and the pressure (in atmospheres).$v_{rms}$ =    m/s    $ \times10^{-22 }$ atm

  The lowest pressure attainable using the best avalh6vrd n,99crqpjone 7 1 v ;(xhwig-09kw xa+ilable vacuum techniques is about drx9e+1oi90 xgal9wr -,h vnpv(kqh w6j7nc ;$10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his l7d43nn q) hu. zbpwi:gungs to full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if hehqpun :g7.z4d n )w3ib quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a speeg f:fq(hj+j1j cc8 fh-f:lg y(d of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperature? (Because of this high temperature, the nof1:flc jyhgfhq8: j+ fj(c -g(se of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increased fj::o n7 ,6m7edz csqxzrom 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 77 4w:irq+10omulhi v i-0m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric pressure at the surface of the Earth, estimaa/cglv0m1gp /(v dg x:te the total number of air molecul x1dcgamp :0g(g/lvv/es in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitce6ng x:9(emzpq +r5nrogen molecules contained in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in afj:pl)80x l-.jum gla hospital has gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospher:)xplj mfj.g-ull80a ic pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of liquid mercury4jb+;5om xk ,onr8ph y at 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasolin dvjq2z+ 4xsh;e at 0$^{\circ} $C is 0.68$ \times10^{3 }kg/m^3$ What is the density on a hot day, when the temperature is 38$^{\circ} $C?    kg/$m^3$
What is the percentage change?    %

  If a steel band were to fit snugly around the Eu59x.jis xgjl 4z. n fxge l)t)sm(7o,arth’s equator at 25$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws th)exbe/ j 58kv-fcie0ightly onto a glass jar at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopted ink b,xay)sgf tmr:k06- the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, h4f4aopbpwd*z 2.2l hn,hqp .q as a pressure of 195 atm at 20$^{\circ} $C. The volume of the tank is 11.3 L.
(a) What would the volume of the air be at 1.00 atm and at the same temperature?    L
(b) Before entering the water, a person consumes 2.0 L of air in each breath, and breathes 12 times a minute. At this rate, how long would the tank last?    min
(c) At a depth of 20.0 m of sea water and temperature of 10$^{\circ} $C, how long would the same tank last assuming the breathing rate does not change?    min

  The escape speed from the Earth isx l.ab y9fd7kil-6y5 l $ 1.12\times10^{4 } m/s$ so a gas molecule travelling away from Earth near the outer boundary of the Earth’s atmosphere would, at this speed, be able to escape from the Earth’s gravitational field. At what temperature is the average speed of
(a) oxygen molecules,    $ \times10^{5 }$K
(b) helium atoms equal to $ 1.12\times10^{4 } m/s$    $ \times10^{4}$K
(c) Can you see why our atmosphere contains oxygen but not helium?

  A 1.0-kg trash-can lid is suspe0yk;(0eq + ft .zfh 5brktv:nxfbr:l+nded against gravity by tennis balls thrown vertically upward at it. How ma5+rffy0.vtn(ek+xtkh l : bf zrb:;q0ny tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-4xac *kldcv;+ 4djhz4diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the tempe4z*dl;4k+cd ha j4 vxcrature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reaches the surface?    cm

  Calculate the total water y goh69r:1rfa6obn6 rj +g;kivapor pressure in the air on the following two days: i1oja6borrfgrk;y6g n6 + h9:
(a) a hot summer day, with the temperature 30$^{\circ} $C and the relative humidity at 40%;    Pa
(b) a cold winter day, with the temperature 5$^{\circ} $C and the relative humidity at 80%.    Pa

  A sauna has 7$m^3$ of air volume, and the temperature is 90$^{\circ} $C. The air is perfectly dry. How much water (in kg) should be evaporated if we want to increase the relative humidity from 0% to 10%? (See Table 13–3.)    kg

  Estimate the percent difference in the density of iron at STP, and when it i*ord;pcgo 8i*ou45 w gq/i6kps a solid deep in the Eago *ipgdo4krq/ c;6w i5 *pou8rth where the temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gapyi4yol*98hul3zp y p1g ne*.s law to show that, for an ideal gas at constant pressure, the coefficient ozyg3 9y 1lpl *op48ieyu.hpn* f volume expansion is equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.