Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic tablc1 zxu*g)ec /oe or u/ zcoe c)x1*gAppendix B.

Name several properties of materials that could be exploited to make a thermozeqxmd (8j61 ; cpbew8zqt t/q6g91jjmet9jdqp zjxge ecqb6j;1z(tt /8qm68 w1 er.

Which is larger, 1 Ctk z9t m/0zt8s1 zt9wx $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with systemcl j:n+ii.pk+ B, but B is not in thermal equilibrium wnl+j :c+ki .piith system C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a str4*xj cpgtq;: sip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: See Table 13–1.] Why?s:tcxjq4;g*p

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 co kj:zs+gjnm0* efficient 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 simpa4fn umgw *6mad+wq ) cp+tg34le 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 * mgq 464+3mc d)p+auwawfnt gmercury 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 temperatures.

Long steam pipes that are fixed at the ends often have a sectiodl4 (tx x/dk )0lcnge5n in the shape of alxdtdck0/e5) (gn lx 4 U. Why?

A flat, uniform cylinder of lead floats in r w1s cexx*tb-169k yqmercury 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 wagmxgwb8l9: .avkm0 w9ter, the mercumlmg.xg wk09b9a: vw8 ry initially descends a bit and then rises. Explain.

A glass container may break if one part of it is heated /hf7bymus0r q/6dv 2 gor cooled more rapidly than adjg0yhvd/ s 26mq/bf ru7acent parts. Explain.

The principal virtue of Pyrex glass is that its coefficient oez9yzb yg9r :kkw.- 0dg v,7ywf linear expansion is much smaller tdk.y0wgr vw9bz g97z:ke -yy,han that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accurz .y-lwkqst,tp xr:., ate 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 fml1cuw2r; :s wx)) mtcause its bottom and top to bulge so badly the can will nomuw21cx; )ftr:)lm ws t stand up. What has happened?

When a gas is rapidly compressed (say, by pushing down a piston), its temperatur( rxr-8fs;bk we 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 when they strike thebfrw;8s x- r(k moving piston.

Will the buoyant force on an aluminum sphere submerged in water increas tsaj 5.83zijde or decreadj85.z sita3j se if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and thfr,m*c f l86ehe relation between average kinetic energy and the absolut6l*r fhfcem8,e temperature.

Explain in words how Gay-Luuc*g( jzfo ptse- ;3.9xt yr+yssac’s law follows from kinetic theory.

As you go higher in the Earth’s atmosphere, the oyz2i f2tdz+ b0vg+i +ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must 5:ri6rd6q 2 rmrxj ,iy;/m)brwp9nhb 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 smaller mass. Explain why tnb5 rw)rhr;:b2ij /ir9m r6,yd6q pxmhe Moon has practically no atmosphere.

Alcohol evaporates more quickla:8 is7 swg4v.fnid3ly than water at room temperature. What can you infer abousig lv :78 daf43iw.snt the molecular properties of one relative to the other?

Explain why a hot humid day is far more uncomfortable c*r9+5u 40tb*awt(ejezaz7k ;p dx 0h gxunw 6than a hot dry day at the s5nba d te*wwtzz(x6 rukgju7 a+90cxp; eh40*ame temperature.

Is it possible to boil water at room temperature (2c s0bgsr-e6 (p0 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temper+3jzz( hb3t dlx;6ijaature is the same but the humidity is different. Which is more dense, the dry air or the humid air tlz3+3z6had i(xjj b; at the same T? Explain.

Explain why it is dangerous to open the radiator9i9n ry-mu8qw5 bny5d cap of an overheated automobile engi9y-8uqn5brm d5 iwny 9ne.

Why does exhaled air f :wz lz*h.ho-appear as a little white cloud in the winter (Fig. 13–28)?

  How many atoms are there in a 3.4-gram copper x+c1o-wqln/p za4 cgtx (h/ k*penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26zqu80p i*)v+c )krvx33abd v6c hy ;yv.5-gram gold ring compare to the number in a silver ring cp k*v yy x 0vr8divv+acu6q3z)hb );3of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. Whatam5nd;l+q9 :ea lm9yz is this on the Celsius scale?lq9z;a 9m5:yen +ald m   $^{\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 temperatures recoras bem9n35i9 2wq7v dx3-ezuj ded 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 lengtm4t x89b*:gjl xw:dh vh 11.82 cm at 0.4: w8 tx db:glh9m*xjv0 $^{\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 s xzg59v:9ofyb xah)n4labs 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 wroudv-c cdahv.m- ;u* m08j ac a8zx1qdrj2:5iykght iron approximately 300 m tall. Estimate how much its height changes between July (averajrvz8 c-ia adu25j81c:v kmm0qx.*dy- dh ;cage 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 o(kg9fq tc0d c82u6xec ften used and the rivet is cool g9ux 82 fckccq06de(ted (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 qum *d*3 liqax*is; :m4 $^{\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.cyjegtjzu 31; x-hj:v+ 3 am0d What will be its change in volume if it is heated frod3:majh 0y uz g t-xvjj+1e3;cm 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled 3vidyrwk*.6 m w2zg3:gl g8wdto the brim with 350.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL ofhe k/q 0iv/2 yss2(q(3zs hfvcfzl/+r 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 ir n:tfutc3y )-zon. 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 xh/d,hl1;z ulvessel so it can expand in essentially one direction only, showlu zhh lxd;/,1 that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the densite2 eeq/k y)t6wp4h9 xey $\rho$ 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 coefficient of linearzudk.+4n 4eh (u2upyzd7lk 7i exp2zk kduy(z.7euphu 4d 4ln7i+ansion $\alpha$ 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 iqgr rbz5pik8+k9bmv z1*,ru 1n) ym2solid, $\beta$ = 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 brad+bm+pw8f y l+ sifl5/ss and keeps perfect time at 17 l+mybfl+5p+d sf8/w i $^{\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 insidf0j.i 8l3mr2v cq sw5re diameter of 0.140 mm. The bulb has2rfj8c5 0wq vsi.mr 3l 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 cylindrical wheel of radius 0.41 m is rotating ab9 jp2k4(-r6p1ydz:/b skcatgkdh8va out its axle on frictionless bearings with gdk 2 b8vzp4ahct/dypk1j - (9 kr6s:aangular velocity $\omega$ = 32.8 rad/s If its temperature is now raised from 20.0 $^{\circ} $ C to 75.0 $^{\circ} $ C, what is the fractional change in $\omega$?   

  An aluminum bar has the desired length when at 15/y) (p*jnw pf d2q-wbj°C. How much stress is required toy wd)-w *j2bq/n(pfjp keep it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of cross-secti o.mb/yf.g n yjk/4oj2onal 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 cel;uq +lrvs)1znv 58jf+p9phm at 20$^{\circ} $ C is to be enclosed by an iron band. The circular band has an inside diameter of 134.110 cm at 20$^{\circ} $ C. It is 7.4 cm wide and 0.65 cm thick.
(a) To what temperature must the band be heated so that it will fit over the barrel? $\approx$   $^{\circ} $ C(Round to the nearest integer)
(b) What will be the tension in the band when it cools to 20$^{\circ} $ C?    N

  What are the following temperatures on the Kelvin :magf a 1a6r ogu*ie*7scale:
(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 xux nmc 3k 6/nywva*;aq-+f8gFahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and Sun are about 40jv)wu(u pw57 l00$^{\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 atmospheric pressure and a vp0 9jln z)/3/xc hpfltemperature of about 20cz lp3vp0j9)/lh f xn/$^{\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 oxyx y.8c5x teff- xow7au+q89jxgen at STP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitroc wa(o) h)bc4ygen ($N_2$) 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.jlxz/khidhr/ hcr3xk16b ( 575 kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gamqoug:ktt fp.*z, / iqaf+x21s 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-Lfbv8/e(9f qbqv z*x x6 container holding 105.0 kg of argon gas at 38xq /b9xfz86qfbv(*ve5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg of6vpoun1 n8 w7gt tq8l0 $O_2$ 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 buo+- bc1)mrkbzlgf) njfn51an 6yant lift by heating the air inside the balloon, which makes it less dense t gkm )r1-n ncf6jz)1 f+ablb5nhan 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 ap*dlz ded9,a w x/24dst 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 18s 1l:bi2ql jn.p77 vdy/a8i dc.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 ch lxjk l,w-:k+2 nptd6nild’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 of10 7mute *s 2ma0wusjhd7bq.e molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many molecules? jc/aky/qxu75    mol    $ \times10^{25 }$ molecules

  Estimate the number of (,yd 6e)p /q3p0gdji wpa) 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 volumewafpg5)nw(wb.xg x(/a/afp h 1*j x2z 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 arko7sq,6 wg: i6;gpvniedne45e in each 2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphernio64ignk :wpe vq;6eg,d5 7se is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energyod / w+77gef(vq/ fgfj of an oxygen molecule at STPfg (/f7vfegwjo7qd +/ ?    $ \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 heli ph3m62 fo(hk.cy hfi:um atoms near the surface of the Sun at a temperature of about(f3khomhp:f i.6cy2h 6000 K.    m/s

  By what factor will the rms s0bbbb zl9w;/8/v erw9q ogv1wpeed of gas molecules increase if the temperature is increased from 0 wberb;olqz//w9 b09gv8 1vbw $^{\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 units5rzr.w uk -5ac of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Cal-zu.r5r 5kwcaculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas at 20.0 a4mh4c5v tg w)$^{\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 volc; ssc 4)bs3ycume is held constant, by what factor yc;43cc) sss bdoes $v_{rms}$ change?   

Show that the rms speed of molecules in a gas is given -h . nsp6 ,umarz.z- awxi+z)fby $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases at the same temperature, the ratio of th+i54 u zg.c1ff oo9*+jtye dzaeir rms speeds is equal to the inverse ratio of the square roots of their molecular 1f gto.f 54za*e9oz idy+uc +jmasses.

  What is the rms speed of n+a ghpj ztjl)1(-iyk (s9xu( hitrogen 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;j :lhry r74d bhwi-du-+*swh 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 4 )8kp16tn6m u(h cywzih ,zmdbetween nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 839urr8d w2 oxw9 u in a living cell at 3283xwruord w9 7 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressure P of a ga8jr2+ ynou/qz s 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 ura-y+;vpa 5aocrnium, $^{235}$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 9c2vwo yoad su0q 9w/6phases 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 tnughc2 :4m *:s ofxg1zhe temperature is (a)zgx c41unm*o: g:f hs2 90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the hu.usk 3 wgkv7i-midity is 50% on a day when the temperaturk.sgk3 u v7-wie is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where waterlp) l46yahd o8m4gb /h boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm,:46ebh u0nk ca estimate the temperature at which water boils4unhc e:a6 kb0. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the paqn7fy/7yh.)gf uysz 5rtial pressure of water is 530 Pa and the relative humi75u.yz7/ )hy yqfgsn fdity is 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when the temperaag5; cx advs+0v-ssd0ture is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximat./5pb cx7* pu +1dtq ci/dxq3w;fvfyo7lnj9e e pressure inside a pressure cooker if the water is boiling atd;xf*/qv p/x71 ten73bj 5yfcqipld wc +.ou9 a temperature of 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a room of volumeo,bfp0z lvm2h2q-t; u 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 point of ydx4:f 3i+vztwln*b 9u;x0 iw 7f nio(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) z4( yz9*o6h ,dydg nsqto diffuse a disz9 gnz yy6dh (sqd*,o4tance 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 tx3j3 ghacx;) hhrough tiny tubes calljx 3h3h axc;g)ed tracheae. An average trachea is about 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 measure has,iepo+8t) (ulvh u8lwc y *93fkco0ai 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 tapetn ; arr j 3(vy-7p.jli1in21mhba:r k 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 room temperaturp .1axb1am1gr c0 fc)lt xsw11e. How much error willfx1 1argc1a 0mpcx1sw b.l) 1t be made in a recipe calling 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 cylinder is ini a*- p.fnxbiz4tially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas r-pb*nix .4zfaemains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.1 /gzp1+n(r-tq4 vjps um, and height 2.5 m. Assume the tempera4 r+ u1g-npt(/vq zpjsture is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density o/ ,5 cy7yio ..7hgrpx/wyvpruf 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 avail txp+hz5c26k1o42e g0/uve skw(jwclable vacuum techniques is aboutoj +2w/6kceet xkz4 5cpg( 2vwhlus0 1 $10^{-12} N/m^2$ 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 capacity of 5.xj;1i 3j*z/vs e2mope5 L when 10 m below the surface, to what volume would his lungs expand if hexj 2v/3p;em*ze 1osij quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere at a spe: 9txwpi3 hgg.ed of about 40,000 km/h Molecules (assume nitrogen):gx 3w .gpih9t 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 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 ct1we xom-,b /increased 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 afg4.7jpe d0qnmo, 7n of 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 t an*6epmc q niuyt2z69u:)q2yjk f,i:he surface of the Earth, estimate the total number of air molecules in the Earth’s atmosphere.qy fuj uiqk nmza,262)tn: :p*ec6i9y    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules contained i :6f9 )jij hbvzmc9j7mn 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 = 2007n9;kuz,yf,j.. b scqb) pklt0 psi (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure.nus f)kz7l;9b c,k . yqptj,b, is constant at 2.4 L/min. $\approx$    hour

  An iron cube floats in a bowl of ld*s(uxraktax(4 j/y0iquid 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 gasoln nqn6z mgfx.m4) i/.kine 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’s equator emc 5y y0 n;ns8icrfk0cbd(l3w1 s98vat 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 ontzoiis17 9;;pt ecb q-to 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 standardj ; 8hu,f s)m5q3ei)bf4dqvjn, vysu8, 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 asr(c +iy2p7,)j fuk ucharged, 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 tgghr/c :): s8c,an ply vq9(o0yrll*ehe Earth 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 suspmr1d cv)qz p5*ended against gravity by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, 5q 1rdzv*cmp)assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubble of air from a dep/p3lw2 :j;x liohliv )e: o/ysth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air bloi/:w v jsy ohe:3x2l)i;p /lehaves 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 following two dayucio b9+ g: edtdmf,2(s: tod9e,ui+: 2dfc(bmg
(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 densivi2-if qhn,y mc4:bi-ty of iron at STP, and when it is a solid deep 4 y m fn:ii-h,iq2b-cvin the 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 toi+:(b3 bqcsqi show that, for an ideal gas at constant pressure, the coefficient of volume expbcb3q:q+( si iansion 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.