Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic tablf/ *3wcfyi1tjy* s8wb7 g 8aube ojwtc*b/baf 8y 8 giuwf17s*3yr Appendix B.

Name several properties of materials that could be exploited to make a thermomet0d j 6zfddru+(khg) hia5b ka)wo 22)v zo+)fhk d vd2(jba)uk25)h6wird g0aer.

Which is larger, 1 C)9ofc0g6e zxl $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with - ybcch0uumrf(9 a(cy1, gp h3system B, but B is not in thermal equilibrium with sysu-h0cg (f(chu3ma,prcyb y91tem C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. 5bu(z kfbc; 0khoo,.26pacjv: hhw nxm;2fl- When heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: See Table 13;lhk.-(a jbo vxphwf, :b;6zc5nokfch u 2m20–1.] 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 coefficient of lla ,*ggi6pf ngm yd24u)k i0b2w(cco:inear 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 simple thermostat used 5:wn ok) -so db:-d utrztv:u3to 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 wires. Explain how this device controls the furnace and how it can be set at different temp5kdznr: odb -u:3tw-uv:s)o teratures.

Long steam pipes that are fixed at the en4fh2 r b;r)vxf leld.3ds often have a section in the shape of a U. Wl4rrvfh). edlb3x; f2hy?

A flat, uniform cylinder of lead floats in merc ;mle2oq/mt fj3a,r9e.dk:p hury at 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 in a hot tub of 76kns 0ccxw+ -sc8gjrt q9+mpwater, the mercury initially descends a bit and then risj-q6pcmscg+twn xk+8 9 r 0c7ses. Explain.

A glass container may break if one part of it is heated or ct4oex;hc 3,bw,b io- vooled more rapidly than ao,3- hoxw; betv, bi4cdjacent parts. Explain.

The principal virtue of Pyryf ; -*:z yvtf82xo*62 vjedkrm+jexcex glass is that its coefficient of linear expansion xc6+mk ;ztf* f jo2*:djyvre2e-v8xy is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at 20 bk-.2tur)(yzv xc:17 ka u ,1 lwnzppu$^{\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 soc 5im;xp a7/oeda will cause its bottom and top to bulge so badly the can will not stand up. What has ;iacx5o7 e /pmhappened?

When a gas is rapidly compressed (say, by pushing down a piston), its tempvbv7h5no fkl58h p qw)v8-ka*erature increases. When a o kav8557np*v )-8vhfhlwkbq gas expands against a piston, it cools. Explain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an akjv 3 ayxpho;z9j 7((cluminum sphere submerged in water increase or decrease; a3p7(z xjo9h yc(vjk if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law fofmt u.s.bc1q3llows from kinetic theory and the relation between average k1qb3utm .cs. finetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law followq6 .o9uilxbp 7 onvij(*p u4xj-pcs* 7s from kinetic theory.

As you go higher in the Earth’s atmos-f5vk+;+5 ngwtp/ dlpg.xkjg g 47xg ephere, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers nhn(z u 0y93i: hig3eqto the minimum speed an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth wha0(iqghn:z93inueh3 y t it is for the Earth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What canpoq*xdy-1 ;do/ 5ld*opo +lnp you infer about the molecul* pllx1no/y; +*po-ddo5 opdqar properties of one relative to the other?

Explain why a hot humid day is far more uncomfortable than a hot drx 0czq/3un i;*19( qodwwunziy day at the same te0;1i qcu(x /qw nzu39idoz*wn mperature.

Is it possible to boil water at room tempe, vba;/gy0auu rature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humiue-u/f f33 jxw:avo y.dity is different. Which is more dense, the dry :ou -vw /.3jyfaf3eux air or the humid air at the same T? Explain.

Explain why it is dangerous to open tb(v 0pce o;d3em,+hvmc6ab3 zhe radiator cap of an overheated automobile engi(cvmdvc hz6pa+ebe0,; 3 3bmone.

Why does exhaled air appear as a little white cloud in the winter (Fig. 13–28)?by7b );.j/lv p* fhffh

  How many atoms are theqi0e2(4su ja zesgd:or (nzh y*/zq 14re in a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number ly l.:f0 -daydge/s0 hof atoms in a 26.5-gram gold ring compare to the number in a silver ringgh yf ad:l.-l/00sdey of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to5lp:1o m u8t-rqird7ex c u7.s9ne9 cbeh23sc be 68°F. What is this on the Celsius scale? :2r7n-osce8si.b 5hu3cd9 rx9l1ctqepe m 7u    $^{\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 lowest temperaturesy) :f lg1vucnp8jmy11 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, the alcohol column has length 1 egrs+q /iwnc5z+* i7x3wlx,e1.82 cm at 0.0 /c z7w n+lxe5,srw3q*exig+ i$^{\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 slag h neldwje-,wt(c/:6qe 5 rp(bs 12 m long (20 $^{\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 iron apprkf;:lok(n9 rnt p:8kdoximately 300 m tall. Estimate how much its height changes betweenn:9nklto( f 8dkpk;r : 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, rivets that are larger than the rivet hole are oivq.y g.;6floften used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet g.fio.y vl;6 q1.871 cm in diameter is to be placed in a hole 1.869 cm in diameter at 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 n 9, xw;qo f0uorx4c,b k jpcpl8o il(e907cv7at 4 $^{\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 cmub6a xnc*1h+2hf 1*ijn.btf g in diameter. What will be its change in volume if it is heatet*ubn*bnf1gfxh 2ai.6 h1+c jd from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL of water at 10+- sfdcid;;xv 0 n6lct0.0$^{\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 mLay*ix 9 3kb16jq ji8hj of 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 made of iron. At -qfog -2x)f3y qcoxlq2hp 7 ;v20 $^{\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 .8ipb5q,upr k 5 pfju.in a long, narrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linear expansion is approximately equal to the coefficf. q pu5ib pj5,kru8p.ient of volume expansion $\beta$.

(a) Show that the change in thth3 dxvh p9,o*uso7m7) 6lnv re 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 has coeffic6mjlax(f bhklu0 kl,-,u 5z 8vient of linear expansion5-u0la 8(6llzvkmhb,,fj xuk $\alpha$ 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 solid c2zh blbe euz-9zy:/,, $\beta$ = 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 made of x9(-khatk066iwe2ae b7 pumt brass and keeps perfect time at 17 6-7ih ptxutmk( k9wee2a6b0a$^{\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 mm.ikl d+ 8 n5 x4c2qy; hgkr/z.;pi,nncl The bulb has .p g2d q4h;z5xnikcr; cnl+, /lykin8a volume of 0.255 $cm^3$ 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 cylindrical wheel of radius 0.41 m q9f52m8vjydivt 7 kr,lo ds.2is rotating about its axle on frictionless bearings with angular velocit5mitfov qjl,s27 vd2. 9k8 ydry $\omega$ = 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 desi5qofa)y r64 lxo (/ g6ljfkqt:red length when at 15°C. How much stress is required to keep it at this len/jf4tl6 of qxqo)y:6 (l gark5gth if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectioo4( tk i2te(wsnal 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 134.122 cm at 2w )j2pwauj jow11dr 0+0$^{\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 temperyapa+zyd5ivci fc--h7 yv- j/d*)0ao atures on the Kelvin 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 tempem tls-d rxbt: *72lc+nrature on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth an ge*uer/;5w ;sp ao-yid 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 engine, air at atmosphete;-5xk5o8 c-h6 vtthitf1wlric pressure and a temperature of about 2;theitfth-ovt5k5l 1x- c6 8w0$^{\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 law6mkikqj v/a5;u 4isz1.    kg/$m^3$

  A storage tank contains 21.6 kg ofy -4ych/h,(-ogv)zxcjte4 yi 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 contains 18.5 kg of nitroge:k8+rka cp (nx jj*d,cn ($N_2$)
(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 g),jz,j v yg. h9tw0csias is at 10.0$^{\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 105n8u430bi vgvk .0 kg of argon gas at 3853 n8vg4k 0ibvu K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 klk-dm(vf7v+f pj:nid u +ujp.d/:7)6b ydds ng 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 inside the ballooc -g,.9j3glfh4ljmz z n,9g3j,-z.hlz4cg j mlf which makes it less dense 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 1;;: 73amu; mppa cxxp. y8afyn qz3mm)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 atxmi(g 5u8)ycd 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 balloofs)3iyo zgb 7q;ii/dcvkq11 2n escapes a child’s hand at sea level and 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 of molecule:z)3 u.vzgw/y(d f wnjedbtv :sn2 ;7qs / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are the,q*cwe eckdp --;z:,giv cru6re in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number oqp9,afs zd.c;4z r0x ; u .hrhi4;vdqnf (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 volume(youvuuj. ms )*wf.: a 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 breath x2b/em72eq.bcuh uc+you inhale that were also in the last beux +h/cq7b22cemu. 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 ke*6 mgsxi75mgpro3 m)inetic energy of an oxygen molecule at STP5m6gie rp m o7s)3x*gm?    $ \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 near the surfaceykbhoevp.w8+ cz:ml xvei,wgp6 5 dr)45qw/9 of the Sun at a temperature of w.k h+bm8 e9 p6gx cyvd5zvw/ 54wrlip :o,)eqabout 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the t gfyzjpd6 h6+2/d4oh g 5di3tf9sjm4femperature is incregg+fot4 6jd25fdfzi p 69yjs43 m/hhd ased 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 speeds, given in u94ul,wkpo6 cz jtw1 3cnits of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate tj3ol zkww c1cpu4,9 6the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas at 20.0 1- +6wzq(i6wjemmus g 8ili7 9)vzhd:bpfq*j $^{\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, bys/ 3i.god 4cgv what fs cidov43.g /gactor does $v_{rms}$ change?   

Show that the rms speed of molec b l7cm *doq3q3+lnw1rules in a gas is given 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 th(+fg vmcb e3xig 4m++9d5yv(3adl i ile same temperature, the ratio of their rms speeds is equal to the inverse ratio of the square roots of their molecular3g (mb+3 e x4d+a5ycf (di9iil+vml gv masses.

  What is the rms speed of nitrodl 8gbeo6f :*x)p,guggen 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 an oxygen molecule at ds8xiau5i 0q; 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 molecrof+ ra5-2lvd ules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in a lid mxwu n4nw2*3ving cell a*32xd 4wunnwm t 37 $^{\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 (cqtpdzxg, 4k r80i+vP of a gas 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 47b3ibs*s *( qwty;tbzmu 0gruranium, $^{235}$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 what phi-*-5cvyja nib i-dbj x*2- vtases 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 the pd nyi ,ybui+(t)cuan7y8 b:g8ressure is 0.01 atm and the temperature is (a) 90i8yb8( cndyniy+u)u7b, gt :a $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if tun*3vif x 4i p+cmea31he humidity is 50% on a day when the temperature is 2 c4p vn1ei3i+au3x fm*5 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boilx6. f0)ypxohrt blpw* 0y67vis at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place ivm;4g.uotb8 a q/zv )zn the mountains is 0.72 atm, estimate the ttz;m4)ba 8ouzg q/v .vemperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the v/izyt2m1s2 fpe(.a wpartial pressure of water is 530 Pa and the relative humidity i(m/f2aipt s.e2z vwy1 s 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the te 7ss0bwsz65qr sh,lp es8 h6y1mperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the water isogu:8o;)j 0o 3nvbplm boiling at a 03p8boumg:)jnvlo o ; 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 680 1jcfe/qpnl9 y.3ewy8 $m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew point8bm 2ubutwf5iz: i.5:esu3r16dv wqt 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 glycine molecule (see Table 13–4) to diffuse a)eu xsd +rr erg;*prvmc7sz)x, d0v47 disze0grue+d) csr7pm; )sx7*v4 rv dr ,xtance 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 interior through tin*9k0w ck(u zxexx9g r6y tubes called tracheae. An average trachea is about 2 mm long and has cross-sectik0u kcr6(*g xxz9e9wxonal area 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 hasis jexmp 60ccbe:7-0w 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 calisy1i q(x4qm,d brated 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 room temperature. How muc rcmry ,cz tha.jj2;)py;6:7p sctd)zh error will be made in a recipe calling for 300 mL of cool water, if)cha:7p my z,dcs; ;yt)cp zjrr2 6t.j the water and the cup are hot, at 80$^{\circ} $C, instead of at 20$^{\circ} $C? Neglect the glass expansion.$\approx$    ml

  The gauge pressure in a helium gas cyl i pzg:rg30te;inder is initially 28 atm. After many balloons have bee;z3rt:g0i epg n blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air m)aqppki 8qexf4(z)r/olecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m. Asa )8pqxp4f/e(zki)q rsume the temperature 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 fg)uaye o u 2:/hkp2jq,7p3pxatom per $cm^3$ 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 availab6vl anzjk3xr9v6v5xa/ t 5j)rle vacuum techniques is about avv96tx /r zr5j j6xn)vk35la$10^{-12} N/m^2$ 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 lungs to hd ojc;v 22uk2zkqq56 full capacity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly rose to t2 6 vq2o2z;q d5jckuhkhe surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a speed of j(r,en1(mf8x ;dvy0t b behn7about 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 nose of a space vehicle must be made of sv n(y b17(8,jdrbenh;tfm0xe pecial 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 increj1v q5wea ye)e +(ccl u6*hym7ased from 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 77axlng*+w md7 p 0zca+70m$^2$ (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 tg:u(vkrbn3m 3i su i 5l5lxg(/he Earth, estimate the total number of air molecules in the lrkiub im/lnsg (xg33(5v:5 uEarth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen or8jx 5o6g7y baplj 3fouw61 ;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 a hospital has gauge pressure)6o4 xqk.s(j.1e iisnocanw8 = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder last jk(ssew . )o 8.4qan6xnc1iio if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of bx7ljm/ c *ltzb*l bow;)3.o tliquid mercury 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 gasoline asv,c7*)bjullx9 r nz *t 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 Eart5x-dw9u,dec , gr uqc,h’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 tight eg94d,bw sib0ly 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 stanurm76o-a,6f i4.jogeeyu -5 k kqls/ddard, adopted in 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, : 16pk+e*ssmeh c7paehas 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 Eart0v r:vxy2l 8mu 4v)a;zccaq3lh is $ 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 suspended against gravity by tennis balls thrown vertv-rn-1z wjm8*v,)a n(wbzj;hrwu .qk (xk e6yically upward at it. How many tennis balls per second m.(w nvbvk681,r)zma*nq w-jhxkrw-j eyuz ( ;ust 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 36/xabc q-coz ).00-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How large is the bubble when it reacxczcq- b a)/6ohes the surface?    cm

  Calculate the total water vaporx,i 9;anjyro) pressure in the air on the following two days: ryn ;ai)9x ,jo
(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 differencrizm18 veo2x;3 ty w7 mxhjuw3c4)wh :e in the density of iron at STP, and when it is a solid deep in the Earth where the temperature is 20047hei hw2 ;3)t cvxmwxmu:jyrzow3 810$^{\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 gas las /vdp(4 vpaa5w to show that, for an ideal gas at constant pressure, the coeffpd45s avp/(v aicient of 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.

  In humid climates, people constantly dehumidify their cellars tox ;ql17 cns yf12her3f prevent rot and mildew. If the cellar in12s qh ce3r f1f;xnyl7 a house (kept at 20$^{\circ} $C) has 95 $m^2$ of floor space and a ceiling height of 2.8 m, what is the mass of water that must be removed from it to drop the humidity from 95% to a more reasonable 30%?    kg