Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the pdx7+ e0a,8 7ndgg)pifyu0 r (gxo q58qmh/kbgeriodic table or (88ge7y fuxgg,gik5rd + p/n0a m)q hd7qob 0xAppendix B.

Name several properties of mater( kc;y*j shgat*63 kazials that could be exploited to make a thermometsyt gkk6*h z;* aa(3cjer.

Which is larger, 1 C (*ji+0gm h,r g 8ciy hj(+qlcjsvw. m3$^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium wi7-f 7,da ytbkjsx ./mlth system B, but B is not in thermal equilibrium with system C, what can you say about the temperatures of A, B, and C/j7. 7sf-xlya t ,bkmd?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. When hf w+ q9rpn;jo8n6zug; eated, the strip will be 9+jwg fzoq8;n6;rpnund. 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 coefficient o9i0 l.l;d mf ti wmv ipu;y4(uiggz:66f 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 simple thermostat use(x op)l68spa rd 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 wires. Explain how this device controls the furnace and how it can be set at di oxsap)lr6( 8pfferent temperatures.

Long steam pipes that are fixed at the ends often have a senh y3 oq.io *vdr3w(cv:xb(o2+a3 wjyction in the shape of a U. Why?id(brnoyjhvo(y3* o q:c.w 23 x+vaw3

A flat, uniform cylinder of lead floats in m0c wrw:wyre9l,5eedeb)hu8 2wbz6 q,ercury 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 water, m:3ek1zsr r57p xq;24qzxxkb the mercury initially descends a bitx3zkbz75rr21sm4x;q : qxkep and then rises. Explain.

A glass container may 2iy 5 i5pelrwz28 hgg-break if one part of it is heated or cooled more rapidly thanh ip5gieyg 852-rlz2w adjacent parts. Explain.

The principal virtue of Pyri t2d2jkfi;d0 crayb 51z -4n:xdl7g xex glass is that its coefficient of linear expansion is much dl5zy kx:nc- 7f0i g;2dt4 b21d iajrxsmaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clocq swhb-n lrp/g* ua :d4)lr7:ow3j* uxk, 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 b83uhv4 pvqm j(7y8h*u:0hkoqr 6qbxiottom and top to bulge so badly the can wilqk8uqh b ojvxmi4hquv0r3:6hy 7(8 *pl not stand up. What has happened?

When a gas is rapidly compressed (u)tgjrvj6 2r;8 ryv,q;6y baw0v+luu say, by pushing down a piston), its temperature increasqrr8lva ;u6 jy j6 ; utb,y2gv)0wuvr+es. When a 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 aluminum sphere su+y5-r/kj uwwhw p7 q2+mph3f tbmerged in water increase or decrease if the temperature is increased frr7t wf+k/5+2hw3h qwujyp -pmom 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kine)f0a,ts , .m r)qscozjvnsp2xpu,8 b-tic theory and the relation between average kinetic energy and thejp8t)osbsru 2qsv,x, fmn.z)a-p,0c absolute temperature.

Explain in words how Gay-Lussac’s law follows from kintmr3 cg16*a xtk ao+5netic theory.

As you go higher in the Earth’s atmosphere, t4:+vfi:s1svdd x c ep5he ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum s-q- tj7drea7tph06 b bpeed an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Eart7b6b qdattp-hj 0r-e 7h due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quiclme -6bu m7b0akly than water at room temperature. What can you infer about the molecular properties of one relative e-lmab um6b 07to the other?

Explain why a hot humid day is far more uncomfortable than a hot dry day at the*yp aw44n e+r,+zyezz same temperzyn,4++y * wer4 zapezature.

Is it possible to boil watemfw*mx8n0 r nval36 w*r at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the ai7(.nqo j)ei3:jam xl ir temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the 7xj)i(e 3lj. oqm:ani same T? Explain.

Explain why it is danger,9w;4v.rvi 4 i:yt zsrekj:czous to open the radiator cap of an overheated automobile e: wvy4rjvt ;, zkii.sr4zc9 :engine.

Why does exhaled air appear as a littl*t0 a,s.lq88maa gctxe white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram cop)d*i3rl r* gbl syn)x;per penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the number +nupuo+(krf lu w3 i-*in a s-in (lru+* ukuwf+o3p ilver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this h.198 ygypjmhon the Celsius scale?pyhh 19.jm8 gy   $^{\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 tempera/ afy rj4af;*jtures 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 ther;d+4 z akcog+(xaa6sdmometer, the alcohol column has length 11.82 cm at 0.0 +zcdg(6 o+aasd axk;4$^{\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 11v1f pr2p.ct f2 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. 3 / hs.e/sg8n:n/rfr tw7soux 13–29) is built of wrought iron approximately 300 m tall. Esoxsh/s/ w8/3g.sr:7rfetn nu timate 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, rivets that are larger than the rivet hole are often usvj9o4l /s-cek u(e l-vrp9vd:ed and the rivet is cooled (usually in dry ice) before it is placed ie-u(v/j49rvd klspv e9: -ocln the hole. A steel rivet 1.871 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 /oosf a,yh2y2x0o5kee6m-bj at 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 cm in diameter. What will be its change in vm 81ea r(*sw t4uyj;4wx-yszxolume if it iut*rz(ssa8ex4wj xw-yy; m4 1s heated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 35ql .oe/.f pd+bqiv3w/ 0.0 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 watt/q -asrn d945t, olnw+h8 ktker 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 placedccsvv60lgwy b )9.0xsc +dsec s4x.6:8auyah in a ring 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, narrow vessel so it can expand in essene 2q:,14x -yijpx)ijg uapc.(zf mg9otially one direction only, show that the effectca9-jj z px)i ,g1exqpof yu42i(.mg:ive coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change ipj7)*6ztk 6 9xc1i tkodw6nsan 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 rectangula ,u jioumvbns9 34curuv04c52e58 ow or plate of length l and width w has coefficient of linear expansion3 bcv5482,9nri0ojcwuuv suoo4u e m5 $\alpha$ 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 isojh8tcq2bms + ;tropic 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 made of brass an :qq vfs5ig)imo 9t7ljr 1,l(vd keeps perfect time at 171io vlq it l97 :,mqfvsg)jr(5 $^{\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 a;h0mh ): mlz zmb:wto3n inside diameter of 0.140 mm. The bulb has a volume of 0.2z) boh:mmtlwm30 ;:zh55 $cm^3$ 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 is ron8u (z /e)ycnntating about its axle on frictionless bearings witny(n c8zne)u /h angular 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 when1/ wevrmfis ukug4q*- /eb0d-0to6bu at 15°C. How much stress is required to keep it at this length if the temperature increases to 3o*1/ f-uum0sewvik-u0er6 / d q 4bgtb5 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-sectional area 0.04rczu:yg 0 1shhis/,*v1$m^2$ 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 k 11q ejxm*qk2)pjwq 520$^{\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 temp8bj pow4g lb m*vce;133upk* reratures 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 temperature on pxnrsjw m((2(y4*estthe Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of tqyj6 tltvcz,)nlb 45fd 4f(. db(2dcthe Earth 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 engine, air atooxgra.,bnw+r x-ote:l:q 01 atmospheric pressure and a temperature of angw, - :xtool:ebro+10 arxq .bout 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 th)-nh sj9m6mc x/5akfue ideal gas law.    kg/$m^3$

  A storage tank contains 21.z d0i,qb+tf+yt /e4gq6 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 contains 18.5 kgpxktj.z65i.i0z a yt- 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 heliumvty(r rs fjum;s)go n)z2 74vnqkr)+7 gas 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 612zy)8 4kp /u.bdm uogcsdivgee fp0-3)tot 105.0 kg of argon gas at 38 e4306z8o1cg)tkeub)pod yvs tg2- f/.dmi up5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 lgr5t uofp ,v7gf,gjbm 0:42pkg 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 liuxsqn1a4:r qa 2tcj0b 0gvz6(ft by heating the air inside the balloon, which makes it less dense than the air outside. Suppose the volume of a balloon is u1q(046c xzgrjq0ba2 a tnvs: 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 -ja:y8dqu)9u9 i s drm -y2upl15 $^{\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 np : ka 22t-mfolktg0;at 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 tvy- dth.3z0kescapes 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 molecules u)r,: sv,rieq cpqb .lic.8 8p/ $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there 27w;ry jp-kvr in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) a0tp4 3ll,7ef ryqes )3ghq k;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 5pork 6o 1t ,zzlego;k5z h-6g9.1$ \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 you5++ j(h-hemt 9tr; baen4eaj n inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphere is about 10 km high annja9+54t arn-ejee( htm; hb+d of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen ltr+t;pfg1n v+u*fs( molecule at STP?l g *f+sr1;t(uv+ntpf    $ \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 surface of the Sun a.-a38yq )z) apj qjigst a temperaq. jy- s))8qa3pzjgiature of about 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if. g:d xdvmvl-/ the temperature is increasex:. vl/ d-dmgvd 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 units of km/s: 6, 2, 4, 6,5w 0tqrj-v .,3r9zfo.aa4dg iuoyiahud 107i 0, 4, 1, 8, 5, 3, 7, and 8. Calcula 7 u. u 5jada.zo1griqo4h-9di atyv0r,f3wi0te the rms speed. $v_{rms}$ =    km/s

  The rms speed of moliv rw3;hsr4 l +p8kk+hl:sri :ecules in a gas 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 isb)vk fl 2d6 (vflcmq,. rw747rvf-xf i held constant, by what factor 7. fq,lk 7- fvlfvr)4rxd2i6cf(vb mw does $v_{rms}$ change?   

Show that the rms speed of molecules in a u(3 2llql,0o2yg cssw 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 gasop:3b3i l f-l i3m fq3rl 5)0fux l:prew8pp1aes at the same temperature, the ratio of their rms speeds is equal8e3r-uo : 0lwim3pri :3fx qp1)lp5plbf f3la to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molecules cor9 e1-lgy(j c4k5l fk1hpzu-s ntained 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 se c* bz)qv 30mjj.2wqnpeed of an 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 dista qhbzbt64)-6xxdak3j ;+ya,wme t:9gf l;g gpnce between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass ri51mo 8iwj1u is 89 u in a livij5 i1i1r 8uwomng cell at 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 pressure8u nwgt 2a)9nz4u1 odf P 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 urani;sl.l 3z;7 qmgx(q szdum, $^{235}$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, ir yho5;w96xxi n what 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 the pressure is 0.01 atm and the 6g4h t9r,f er,(xa eaf5qv q(otemperature is (a) 904r(t6x,h 9oea5 agq e (,fqfrv $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a dayr8r*t;rp; *sep 5l+su.zpggk when the temperatkt 5e *lrr *.us+g z8rp;sgpp;ure is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where wa 0h/.qr913kj n9ppppzs0uws y ter boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a peb*v ga+ffalf85*zkux;v x: f42l s3narticular place in the mountains is 0.72 atm, estimate the temperature at which wen*5f2f 8 x; saau3+lv b*fgfz:l xv4kater boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 530b cz2t mh+v)/n Pa and the rzb/mc)h2+t n velative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on gm1hv7)fu-yj4by*r lm tm 25arh+r f ,a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pre 6t*phemqhtj )e up 4.sjj6f80ssure cooker if the water is boiling at a temperah 4p. ju6st*m0fp6ej8ht)qje ture of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a ro z;58e )yv l8g ro8tgf6g/oiyzom of volume 680$m^3$ at 25 $^{\circ} $ C is 80%, what mass of water can still evaporate from an open pan?    kg

  Air that is at its dew poic gt 5i2oup6k vy:)r4knt 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 1ze3n+eq2i8 oaxp83w j3–4) to diffuse a distanceqna32e+e 8wpzio8 x3 j 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 b 5s*a2fov;gj the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has crfb5;o2 *asvg joss-sectional 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 meas4leu r9qzfyd,2b(r k7ure has 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 calibrated lh nue4ls1cmu6yfucv3 24c t):k2-esat 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 fk6e)he+ vrh v3rey.5qs+h ix2 ec88wat normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, 8ve hqvh6+cfx5.w)sek ei8h 2re+y3rif 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 cylinder icnr m2c.tj9i0so-o0a s initially 28 atm. After many balloons have been blown up, the gauge pressure has decreasedjoc0a r9ios.20-tc nm to 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, n8bkn,b 5nb d n+mlk4x)9:ktqwidth 3.1 m, and height 2.ql9 bn+b :k,bmtnx) dknk8n54 5 m. Assume 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 about4*7 3e * * q3zadwkoq8ufanshf one atom 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 atta(m + bzwhoqkzouwlf4(e74 v7 as33 b1minable using the best available vacuum techniques is about 4 qhs bbfv1(o3wu47 +o 7lzz3ekamw( m$10^{-12} N/m^2$ 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 full capa lrhp p/pnd)p152d a2qcity of 5.5 L when 10 m below the surface, to what volume would his lungs expand if he quickly rose to the surface? I2)lp/r p h52dpndq1aps this advisable?    L

  A space vehicle returning from the Moon enters Earl/ ai2 v2:baw( iyml)bth’s atmosphere at a speed 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 nose of a space vehiclev2m/ l wlb aiiy:(ab2) 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 increasedi 8,g8he z1e4 wvk **/yihugcb 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 770guj qp3f3vv4a+ 0no-pm$^2$ (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 -j frr2wx384bka hok: surface of the Earth, estimate the total number of air molecules in x4awr8jbfkr3:o -h 2kthe Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained jt9f oncp(h9(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 ox2p/at 7gl93 4p;bjqutzs rtbp* 7) hwdygen used in a hospital has gauge pressure = 2000 psi (tdaw *pgs)lt77qp/j9bhu3 2p4 rbt;z13,800 kPa) and at T = 259K How long will the cylinder last 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 liquid *q tg7.xown4f;icva/ 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 gasoli,je.)+se;w1ir9u jm)or0gytq mb cn8 ne 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 Earth’lvhwl f)a+ nh2o)x r:4s 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 tightly onto a glass jasea;n5ai4d03 hgvvycv u i1,7r 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 in the zk(j33 ydo:-fbqvpr1 (3f4tqoy mt; s18$^{th}$ 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, has a pr wz,r5fwo/)+v.beu yj essure 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 E;b3 kb vo9f5tae,-haearth 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 again*v*;os 3 8phe2w mrrbyst gravity by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound fromo8prs **2 m;ywrhb3ve the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases ,h0 i*nonj6 vga 3.00-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assu jg6innvh0*o,me the temperature 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 vapor pressure in the air on the yo(k9g gdcqa0+ -ot4vfollowing two days: tvy+ao (d -ko40gqg9 c
(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 iro2l:lz +fp xj(sn at STP, and when it is a solid deep in t plxs:(2+ jfzlhe Earth 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 gas law to show 4g,9 fd4 vogesthat, for an ideal gas at constant pressure, the coefficient of volume expansion is equa4gde,9fo s 4vgl 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 thev pzbz-t s )b09:, dyd)zsgsk4 fhjh)/ir cellars to prevent rot and mildew. If the cellar in ahhgj)y9sdszt /-k4z0p s,b :)df)b z v 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