Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the peez66dt/sy y v82piq l ;ih9)djriodic table or Appesqih vt 6);j2lezd8/9iyp y6 dndix B.

Name several properties of materials thas4pp:cwcmn ) szng78 b3o nl4:t could be exploited to make a thermometsns4cwm 7onl z ppbn8 3c:4)g:er.

Which is larger, 1 Cn cwa.-.3m.v u*-rgg gaox z0x $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B x*r9sa vdu+9ut( n:cfis not in thermal equilibrium with system C, what can you say about the temperatures oftfa9:c r+dvn xus* u(9 A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of 5d/xh62nsujjej(q 3k iron. When heated, the strip will bend. Which metal w6uq/ dj kesj2h5jxn(3ill 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 coefficiw2uc qclw.8ie.3r 7vwent 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 simple th0q8bl 3l6bq 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 b3h0bq l l86qtthat 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 temperatures.

Long steam pipes that are fixed at the ends often have a section in the sh*rkaq+-h y/t.rvt d p,ape of a t,/- h+dpt rvaq*kyr .U. Why?

A flat, uniform cylinder of lead floats in mefg7yq/ keorgt j0.(l)rcury at 0 $^{\circ} $ C. Will the lead float higher or lower when the temperature is raised? Explain.

When a cold mercury-in-glassm e3h2fc4ppsi dv.7+f thermometer is first placed in a hot tub of water, the mercury initially descends a bp2cs 7p. +ief mv43fhdit and then rises. Explain.

A glass container may break if one part of it is heated or coovh9iv kd,51z sh :rd nw71o;shy ;tx)fa.9zwjled more rapidly than adjacent parts. Ehj;dszdt wvzo)y9.na vhx ;kfw7 1r ,s9h5i 1:xplain.

The principal virtue of Pyrex glass is that its coefficient of linea pets) +u*p,c3ulu w-lr expansion +, )c ulutp*suw3l p-eis 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 1/c;9pf. puqfx3xf8ssj q n x9at 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 v *u23jz m3e6 1pi6mc jwul1evmoe7x5q+j 1bicause its bottom and top to bulge so badly the can w1 jqzl bc j63exu6v 2mje3 *ivomi5wm7+ up1e1ill not stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a pistonuu0h7+ jt 2+gndow+ zh), its temperature increases. 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 whe+dgojz 07uu +t+hh2wnn they strike the moving piston.

Will the buoyant force on an aluminum sphere submergek kvmlgsb //u90;4ujk33 ktled in water increase or decrease if the temperature is increased from 20 gvlu; / 3sj3embk k 9ktlu/4k0$^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Cx wnxm-:r1 :ilp ib7h.harles’s law follows from kinetic theory and the relation betwnl.-x1 7:ibxp:hr wmi een average kinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinet dtnqnxjis-)+f oj0)8ic theory.

As you go higher in the Earth’s atmosphere, the ratio oful: ym0ps-)4n9yed m s $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers s8hp loi+ bj26g(9anito the minimum speed 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 Earth due to the Moon’s bjhg8p2+an i o(i6s 9lsmaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperatur ,6z94a xzo c83rr58vodewz gy7rk a*k tbe4u(e. What can you infer about the molecular properties of one relate3 ke, v*446zo5aoary g9du(88xkrtz rwzb c7 ive to the other?

Explain why a hot humid day xgyy9p bi03 4tis far more uncomfortable than a hot dry day at the same temperature y0t9xbpy4g3i.

Is it possible to boil water at roo. (aggw4wewx/ m temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is the same but the humidityi zw/pj*m8y+z is different. Which is more dense, the dry air or the humi wpy+zj/ im8*zd air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an overu6hie4 ;jc n8ygi3/:0w9a pq8tyt wsk heated automobile enginet9c y84jegiw:uia8y0p/; sw nt q3k 6h.

Why does exhaled air appear as a little white cloud in the wyf9 t6z sjw m;90e6ntdinter (Fig. 13–28)?

  How many atoms are there in a z-w5kvc ,5dsixgq7t e 2kcfyw,;o j.) 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the numcu(qi gvs 1gyk1f2n)(ndsbh7 cn 1 b;*ber in a silver ringn*g1;(vd1c7nq bf)gbyc u1(shins2k of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is ofteg6edyaid5h (imv0:.,ez 5ej bn taken to be 68°F. What is this on the Celsius scale?05jvmgzedd ia6b hiey:5.(e,    $^{\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 4ymxs2m/:l; qd sv .2edqv7iflowest 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 +j +9m,l2wsewjdsf ( vthermometer, the alcohol column has length 11.82 cm at 0.w jw+dje2vl 9f,ssm+( 0 $^{\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 ,mk;m dgln60 qkfr. m0long (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 approximately arl-tei p;.5w e83nr52mxnwv300 m tall. Estimate how much its heir2nxe pi53w-e .mrw5n;lta8 v ght 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 toep/eh:vr4+x/oz l 4c1h)stx han the rivet hole are often used and th//xo4rv4hx o zt :1lchpee+) se 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 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 at 4 b-ljtlasdfj l 240 s);gtts/t ;;a )hb$^{\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.lb 8e rb-)/lpn75 cm in diameter. What will be its change in volume if it is heated from 30 p/blbn8rl -)e $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the bri 5(i+xfmz2binuqr,r b46pzy9 m 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 o*tw-w0st5 9v j apc(f*8vq noef 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 fip6e j e-- ,72njpvpma 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 contaiw 0v 1.qx2dd)ah)4ot.vciw f g5 p:ktwned in a long, narrow vessel so it can expand in essentially one direction only, show tha 4o.ivtc. hgvq 5x1)wd) wdtfw0p:2 akt the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the den hezoje 3am,)v0 pcwl,7 cj40ssity $\rho$ 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 l0pr t eq y.gq7o64((a;nyv wkx and width w has coefficient of linear expansion go . 0(e4qaq6 w7yy pkx;v(tnr$\alpha$ 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+ep2 fc+ nra7c1fyjo1 u dn8h/, $\beta$ = 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 and keeps perfect time at 5 1 izfzl:cx5 ogm1r/qe,cokb9x54px 174ikc55e5z,x9o1op1f m/zxlc r g xbq: $^{\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 0.1tvf 2wp00f/ a( o q9ypjkiqy 6eeg1p:;40 mm. The bulb wqayftk(pi ep 0jv 6gy ;12f/9e:o p0qhas a 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 cylindri7ms1a4h0 m yyxcal wheel of radius 0.41 m is rotating about its axle on frictionless bearings with angular veloc04a1x7yh msy mity $\omega$ = 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 uv,5bm;1wrxw:ku uys 9* krt.s) vv g(length when at 15°C. How much stress is required to keep it at this length ikbyx:k,um*sr wswvu g1;)tvr(9u. 5vf the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steez5ed0tefcir 1nmj h d6p6; 5(ol 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 134.122 cm at ngup wc/h6bxaez0 j.8x/i h9*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 s zs9e5b 7 t7f1/epp,x8pf nigon 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 the Fam5zn(mf s4 ywbmd5 :a 92cg/1 dakslj7hrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior o 3t1klihi/a. if the 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 at atmosppf6e:ggm7pbwoc x3bg2im/o0a* n -x 7heric pressure and a temperature onif2-7g ppa0bcbo 7ex*mw6g/3m x og:f 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 oxat fr-mg8w/a ox0v2h f0i+3imd) egt9ygen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of ninavy- pm-,o 5htrogen ($N_2$) 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 18.5l 9r n7a./fiqc 16eeij 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 heli0x3ym(xp m+ t3,u+8tdohj abhum 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; tn,gvp3kfp) i* .ndt.0-L container holding 105.0 kg of argon gas at ),pnv;*ifk .dg3ptnt 385 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of0)59wo* f eme1vi nrrk $O_2$ 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 buoyan yh b8 a.tqoxk8cor;;ir+q* w+u x)-lwt lift by heating the air inside the balloon, which makes it less dense8l-w + ko*tr+;).cix a8 hbyqq wxor;u 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 9i2bvji5d v2vair at 15 $^{\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 at 184 ,cer udp*ap8.0 $^{\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 a:qa)qp3 q qt8ond 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 molcju5yg:o4q q n-m- 1bkecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many mole0 f3b6vwym y8wcules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) m)+l2x 2jnopdpoles,    $ \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 5.1prwbp):iwqy t)in+r 2kj/g 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 80jsd 9zjr :-izjq0 wkyou inhale that were also in the zji 0j9k-:dzqj8rws0 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 energ qemtgiecx dsmpf p:50*8psx;4ne0: 7 y of an oxygen molecule at STPsm n5pdq: *gex f08 ;70xe4pe:citmps?    $ \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 hez-ag5qv- 1qs3/xc vnear the surface of the Sun at a temperature of ab-3-ch sz/xqa 51vvegqout 6000 K.    m/s

  By what factor will the rms speed of gas molecules k4+l 0fagh aq;increase if the temperature is increased4glaqf0a+ ;k h 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 thee1dn0xc9phj gv( 3),ybn0eft following speeds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8.y0f 9bjpxc(dn10)eg en,v 3ht Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of moli2p;5;wu og njnlzk-y t2-93hh;a fidecules 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 is held constant, by what 7r n; gr9,esc7qr f-kmfactorgr-7f , nr 7kq9ms;cer does $v_{rms}$ change?   

Show that the rms speed of molecules g j4 45eh0wotsin 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 the sazj6rds/6y-;2g ox,bw pes 2nmt *qp5s me temperature, the ratio of their rms speeds is equal to the /ospsxgm-jpzs5w*2y;de 62 ,6n qtbrinverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogev 4xp6fkzih ng(xo.xi(bt i5 q- +s1e;n 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 r 79,(ikvovhn;-/zx2tz hdya 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 distance,h ev,qfz :.j+w*tiju;ehgxghx/i0 ; between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms spe(xnm9zvba6v0ge 4r* 1j4wmx g ed of an amino acid whose molecular mass is 89 u in a living cell at 3eg41m zxx90gvwr6j ( n*ma bv47 $^{\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 P8xoai mwpy; +9 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 uran;kh qtvjz;hchc1).q e k7xl+g+wx8- aium, $^{235}$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 whatbw j-xr+9 sg i z /jq/d;gnni-v/c2fm9 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 (9,tduf6gdety(o4e)3h:f4nimsc p h temperature is (a) 9 un(f3t: ideg,p6c9m )oft4syhe 4(dh0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% o/l:+f5 klp u6-r vihunn a day when the tempe/ulir6h:fv 5np -k+ulrature is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils ap6vyw, (3 cv 6;;yakjc jfjvu4t 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in then-ypp1.8 vmcsppr6 ,q mountains is 0.72 atm, estimate the temperatvr1.p ppmqcy6 ps -8n,ure at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when thb:g92m0c bqp2p avpy40dzfv ic)z 0w6e partial pressure of water is 530 Pa andy 42 wbpv00pigfd:p 0)9czbac qvz26m the relative humidity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure o0p ilr/93z6 xbrhw(,8hfgv tof water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximas /xc+;stdxm: te pressure inside a pressure cooker if the water is boiling at a tempera:/ +stmdx xcs;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 roo /ljwxk4n.5z pm 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 d,kprk3:g vn.sgghzk+ jw/( d0ew 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 glycine molecule (see Table 13aq k -9 jo1xnj/5j1xv.l 9vvpa–4) to diffuse a distance of 1a1.9vvj 5j pj1on9-kva xl/qx 5 $\mu m$ 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 surfaav(; urb1c-:lacf (lrce of insects to the interior through tiny tubes called tracheae. An average trachea is acl;a( 1f:rv(ul -cb rabout 2 mm long and has cross-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 me3ma ijrv rfc2f3x7*6 r0z/orsasure 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 tape1(49k av4 fw9ggyflto0esn 6 s measure 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 Pyrex measuring cup was calibrated at normal roo 7dh1hx7etjo*4w0lqczfnx1x1q +x4 xm temperature. How much error will be made in a recipe call07q 7 ox4fwtc1*h4d xh1xqlnjx1 z x+eing for 300 mL of cool water, if 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 cylinde g-/n +imgnpr zg 0 ,rzec-i/9zhc/lo)r is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What frarnnp90ic/ + -c)g,l/zo zzmg ih/ge-r ction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.1 m, g)wa)rbb )8tgand height 8r)a)gbtg wb) 2.5 m. Assume the temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density off d z,l/ry3a0m matter is about 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 attainable using the best available vacuum tec qhl .wpy4:u9yh ev9xcyg *ah *e/v,8ghniques is aboucu/pqvx,hee**:.y 9v gghl hyw48a 9y t $10^{-12} N/m^2$ 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 luwrw)ko t 78gan (8r *cr2*uzlengs to full capacity of 5.5 L when 10 m below the surface, to what a r 7rgut(lczeon828 k** w)wrvolume would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the r th*8u ma.t(iMoon enters Earth’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 vehicle t*mri(8au.th 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 from 1f(j2gfj+bx .r 10$^{\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 os)u/ewx 9x *wxd6n lj;f 770m$^2$ (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 surfac0 /y6e qugx/i i/kvfz-wr2(i:ms5++ umfgwmce of the Earth, estimate the total number of air molecules in the Earth’s atf riqizmvy-x+e2+w6i 0 km: // sf ucwg5/mu(gmosphere.    $ \times10^{44 }$ molecules

  What is the rms speedkg58 f3rhc7bp/-zk d q of nitrogen 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 gaxq1k /tvqa :x6b4k8eyuge pressure = 2000 psi (13,800 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/minqxkvyq eax: 16/8kbt 4. $\approx$    hour

  An iron cube floats in a bowl vn 7 lvu/ )n2)b;pgsolof liquid 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 at bo j+,/fefr hx-7wn+n0$^{\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 th* b* *eqfg+bal+pivw9e Earth’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 tightly onkc 4a q8ur3s9 0m6+ v.)co kaxuft9ngkto 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, a d 8f 9wm63rm u((vi3b+ngokghdopted 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 charge6;7l; gipz7ik/e;gjz m fqe0f d, has 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 uqf6p5*u*,2/o0vw tbof 4 ldc iasw 7aEarth 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 ballsx// 48h3zsf mih+nlfs thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they have a mass of 0.060 kg and a+mhl / sifxn/h43sfz 8re thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cgg v3(if53r oym-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature vgo( 353yirfg 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 o9qt2)( 6 szpzau5 rcman the following two days: zp(u5a asm)2zqr6 t9c
(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 ul1i7zennleq ( g*9)j t )zl0kSTP, and when it is a solid deep in *jl719 nk)(eue0il qngtzz) lthe 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 that, for an ideal gas at constant preso ;- 7 +dh3 nn./xvyuv*vxqxkcsure, the coefficient of volume expansion ;vk3.h* cdn xnvx xov-u+/7 qyis 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.