Which has more atoms: q hme.,m3+n anawz/e08cuy v4x yq04z 1 kg of iron or 1 kg of aluminum? See the periodic table or Append. +vem/wx0qn a0yzyq 3mz 4c4nhe,ua8ix B.

Name several properties of materials that cog;jemao)lkag+ d:k a, enh+3 :uld be exploited to make a thermomet+dengaao+hle:;:3k ja, )k m ger.

Which is larger, 1 C5qk,xi88u, i 8 g vfjyczn9.gdc19y eo $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equi5kcbtb,sdm5zc:;u0d5evx2d o8um5 klibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the tempermz 5:udv;mbc58tux,o0d scdk e52b 5katures of A, B, and C?

A flat bimetallic strip consists of aluminuka2a y3c*uckm r6; 5mft; 2yuqm riveted to a strip of iron. When heated, the strip will bend. Which metal will be on the outside of the curve? [kcyf25;am;qyt3 ra 6 2cu* umkHint: 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 coefficienyhhei; x), wq6um (;tbt 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 sim4upgp6uq e0 u0ple thermostat used to control a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how thisep 0 q4u6u0gup device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed 4(2(zpw si5lujp ydbuds tb:;vr86k6at the ends often have a section in the shape of a U. u 6budy bp6wil;dp82sz (:r45(tkvj s Why?

A flat, uniform cylinder o3 qec rx k6 p40qawpa0ob69+h*ya,od pf lead floats in mercury 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 placejb m/ fu6 r; npkzj9s (1pde85bsc1l2fd in a hot tub of water, the mercury initially pcb65sr( fnp dk;b8/ fzjjus l1 m219edescends a bit and then rises. Explain.

A glass container may break if one part of it is heatjy + 4l4d.7gcq kjwt5aed or cooled more rapidly than adjace 4cjtwkq7.dajgly +5 4nt parts. Explain.

The principal virtue of Pyrex glasxnl00 6/kfh05qimnpxs is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise i5p nfx00k6 qm0l/xnhto the increased heat resistance of Pyrex.

Will a grandfather clock, accurate at 20u bd-2.enov2 9hpf6mx 3ge6cr $^{\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 botto0uwb1v)fd:kfm2: s;b c*waau m and top to bulge so badly the can will not stand up. What has happenedd vbwa: c1uk0:m*bs )aufwf 2;?

When a gas is rapidly compressed (say, by pushing down a piston), its tempe6i t2zzlmizvi*2 2mia;)mq/ krature 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 the ilt;mm2m zk )*2ziqiv/z a26imoving piston.

Will the buoyant force on an aluminum sphere sub -83+;ltc9ydf-efgfqn,bs o*k die:u merged in water increase or decrease if the tebef qd*d9se,-+lug k yi8cf -t;no f:3mperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows froi4+b sj0724 sf x8*imcyek inim kinetic theory and the relation between average k4jc0emfi ib7y4+i 2k8*ns ix sinetic energy and the absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic theor0fmr 9b:jh2*l vz /mfpy.

As you go higher in the Earth’s atmosphere, th/xuvcp,l6 2gphil/* m e ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to thcg2w2af5 5dj./uwee i e 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 smaller mass. Explain why the Moon has practically no atmospheje.cw2a5dwe 2iug5 /fre.

Alcohol evaporates more quickly than water at room temperature. What can yo*.7av qnio3kou infer about vq.o7*ioa3k n the molecular properties of one relative to the other?

Explain why a hot humid day is far more uncomfortable than a hot xy0mr bpv8 j15jix/8mdry day at the same tempi15yxjp v8 0xm/8 bjmrerature.

Is it possible to boil water at ro4e* du3 ,juunhom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperut2-vy6-kg 3l,tegc) tg9b at ature is the same but the humidity is different. Which is more dense, the dry air or the humid air at the a-3 96tggy,ct -ukblve g)t2tsame T? Explain.

Explain why it is datow+20hr0q,531ji oq v bscmgngerous to open the radiator cap of an overheated automobile engij32 sg+1 m, 0bqw0oqo tvh5rcine.

Why does exhaled air appear as a little white cloud j-zzo8)yt yw y7r(v1pw l+j3n) x/bbhin the winter (Fig. 13–28)?

  How many atoms are there ljsveqc5sl rk/g5 e*tl3 03m(; r7pexin a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to nxqtf3sborxia 6u9o/96gdqc ) ;nx). the number in a silver ring of the )/d ;q6inocx939)u. x bxfor gnsa6tqsame mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken to be 68°F. What is this on the Celsiua h /.fj;lvnxt v97v6qs scale?t/l; jf6nhv vvq7a.x9   $^{\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 tempef m0kg1j9slp7jy* o6e ratures 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-glas ot*g0 atiytb7.6 v7css thermometer, the alcohol column has length 11.82 cm at 0.0ito 7vc.7tyat 6sb0 g* $^{\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 +m7t/ l6kf 8.rdkgcql) 4blfh m long (20 $^{\circ} $ C). How wide should the expansion cracks between the slabs be (at 20 $^{\circ} $ C) to prevent buckling if the range of temperature is -30 $^{\circ} $ C to +50 $^{\circ} $ C?    m

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

  The Eiffel Tower (Fig. 13–29) is built of wrought iron approximately 300 m tall.3 h9;pb azea85v(lxad Estimate how much its height changes between July (average temperature of 25°C) and Januaryp8v9a(az;x5abe l 3 hd (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 rivew enpi v,h 12ilvv9v.w0s1;u0 hx0 czjt hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the hole. A steel rivet 1.871 cm in sivpc .nh1v2 z jwxeiv1w,90l0v h0u;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 at5vqe -b*z5ibf 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 gy07omo nt(arv1y2c6: oeg (sin volume if it is heated fro vo(2cnry1mao e gy:6sotg(07m 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 354 4v;z dfjp- kl1clem1 0lviq*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 55.5p3wuhx.1q4:m ojvgtq g:44 h e0 mL of water at 20 $^{\circ} $ C completely fills a container to the brim. When the container and the water are heated to 60 $^{\circ} $ C, 0.35 g of water is lost. (a) What is the coefficient of volume expansion of the container?    $ \times10^{-5 }$ /$C^0$(b) What is the most likely material of the container? The density of water at 60°C is 0.98324g/ml.

  (a) A brass plug is to be placed in a ring made of iron. mr4*xx*uyu:k 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, narrow9e(d)w9:42ccp yfxuu rf/ te r vessel so it can expand in essentially one direction only, show that the effedc :ew/4)uryuf9tcf2 (pxr9ective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the densitoh nziu 11ld:vtdr;euv8, 4t/y v h9f5y $\rho$ 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 coeffici. zr0wrfxb9 +xent of linear expansr0+frzxb w.9x ion $\alpha$ 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 soxxm3pa 8f()h jlid, $\beta$ = 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 -jurvajgcwh4 d45;9 c-b t d(gmade of brass and keeps perfect time at 17 c dhj adwj4gu;crg5t (-v-b94$^{\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 diametr6dqb su 8p k7/q.q*7qg: evkler of 0.140 mm. The bulb has a volume o87*q q.r ek6dgu :lpkq/svb7qf 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 oztn9+c o.2os bf radius 0.41 m is rotating about its axle on frictionless bearingsb . t9oz+2ncos with 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 when at 15°C. How muchywvln 0kl0j (s 3yn8w. stress is required to keep it at this length if the tem3j8s.(0lk0n nlvywwyperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel q1fw:lc9 )3uqd2c p4z47t 08wm qxrimys d c)wI-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 20 u1tm n:q4gk-i$^{\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 sc 9ndmu6l7cuk tv kv/cb.w(c;q:5vhe 5ale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fahrenheit scale a)*a+muzyn/gqy rk/kmj k ,+ 0ncmp87?    $^{\circ} $ F

  Typical temperatures in the interior of the p8zc6x-rjzy 9 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, air4ii m4rr8.l2w qaay 8r at atmospheric pressure and a temperature of8qr28myi i.ra al4 wr4 about 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at Sx 5xk xybn+ 0rr* ;)ct,;8 jh5yzwjh4/eelcru TP using the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nitfpq/gvx8 v; d*g m.6cyrogen ($N_2$) 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 5 vo6d.yqwos )kg of nitrogen ($N_2$)
(a) What is the volume of the tank? $\approx$   $m^3$(“Round to one decimal places)
(b) What is the pressure if an additional 15.0 kg of nitrogen is added without changing the temperature?    $ \times10^{5 }$Pa    atm

  If 18.75 mol of helium gas is at 10.k 7ds.f5)hphsng4tt 6 0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L container holding 105.0 kg of argonfuqg*5le twce7jc8u8j (c + f8 gas at ( e jfc5 *wfleg+8c78qtuju8 c385 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 k4(q9vkc yv/ smg 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 achz r5 eb5ik*m5s cb7igy *;yfeuk.eu08ieves its buoyant lift by heating the air inside the balloon, which makes it less dense than the air igy5c 5imrzuebk.* 7sb f*80eu;ye k5 outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air at(3r7 p2h5z rrq8o(7 jj, mqwlq5ogfyt 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 183*er 0eh -mreo.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 esc5uumjh9 *s ii ,y/yb y kg.,s/elz/0hwapes 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 oft/u8,ucf x/+i kf :t*a8otloc molecules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water a t kdbrstv,7i0x0d4g 3re there in 1.000 L? How many molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (o0caz ,5aj-nwa) 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 5.1 hzlvp6 t*-dv8$ \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 2kc5iri vf, +q1p7 2ank9ru4f o, ey;lj.0-L breath you inhale that were also in the last breath Galileo took.kokr 7,i;q14 ,5 pvrf ea+yuli2 fn9cj [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen molecu v./ncrb26efale at STP? n2 .b eafv6c/r   $ \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 surfac4jxjq y526xxqy) f vlt5fs;d.ip .y h6e of the Sun at a temperature of aj .6yj xlf p.i fyt dv55xy;)24qh6qxsbout 6000 K.    m/s

  By what factor will the rms speed of gas molecules increase if the temp 8s pkt67romh7erature is increased f8hmr76 s7tpok rom 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, zkehp9 7d20 q8xr,hj* xir-re 6, 0, 4qej 8d - rzhh7r92re xkx0ip,*, 1, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules at: s22/0zs rw0bwvkr:da ;za 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, by81k)9biw k,kqqyxo) eoo /,3 bi)tuba what factor does iq)38ky k,a,1twoqe)k9 oub)/i b box$v_{rms}$ change?   

Show that the rms speed of molecules in a ga plb jdvmfk;w1 w7ln:)wes,3; s 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 t3b5bcp8nicdr27 jn k6lz t5s,he same temperature, the ratio of their rms speeds is equal to the inverse ratio of the squarct27cj 6,nl55 ki3zrsbpb8n d e roots of their molecular masses.

  What is the rms speed of nitrogen molemquc-fet5- 3vcules 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 ak3g1 de8d-sok n 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 di z)+tdoi1l 3ynstance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed ys90nkn- oy;a ml w,b+of an amino acid whose molecular mass is 89 u in a living cell l9bm-n, y ks+ynw0;ao 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 pressure P of a gas can 8ippwl (;(x yhbe written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uranium,s: fh.o /sc3ew $^{235}$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 phasesxa -6g5 cuhfuq-4-enrb4bm .t 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 phaser5g;9gs pz7hw when the pressure is 0.01 atm and the temperature is (a) g79sgr5; pz hw90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50%knst)q mlkb: ;rfw; gk(6v,w0 on a day when the temperar ;k6, nsflvkw b;0()wqkmtg: ture is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place where water boils aa ,uzv6 e55kl:urajw 1t 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particuf;r 43qfyy6*kpj m(eblar place in the mountains is 0.72 atm, estimate the temperaturepyem; 3f k4bfy6 *jr(q at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperatu9j:w m)s h-z1 kpvh,/pmf va(sre on a day when the partial pressure of water is 530 Pa and the relative humidity is 4 k fm:wva, j9shs) vhp/p(mz1-0%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial a+v 7zo2 c ynhrh-51mdnu q4k*pressure of water on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure insi1 cpc92 b qqp:k;rfht1de a pressure cooker if the water is boiling at a temperature 1c;q2k br9pc1:hpft qof 120 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a roo(n tcy-wt*h,qj*fu n 1m 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 poinflab p i-.* zr8gvb,ml v 4)rjq/jc/u/t of 5 $^{\circ} $ C is drawn into a building where it is heated to 25. What will be the relative humidity at this temperature? Assume constant pressure of 1.0 atm. Take into account the expansion of the air.    %

  Estimate the time needed for a glycine molecule (see Table 13–wl y.* k:fob k4jp68 hv./lpjd4) to diffuse a distance of 15 jky8p vlh.46d b:p./o lfw* kj$\mu m$ 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 ttgpqz/)9e5ce* hsq /nd i9u4 zo the interior through tiny tubes called tracheae. An average trachea is about 2 mm long and has c4d/ c9zz hp/qeit9*unqe5g)sross-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 d2a-lkde2c*tbeen 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 measp5,a uci22qmmhl. 1uiure 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 cupb;5srd5 xw h-o was calibrated at normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water andd-rhbw5; s5x o 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 initially 28 atm. Apge 7iel)eey 121f+by fter many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraiee 2y pb)+g7 1yle1efction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a c3xm9vndy (u l0d*3 n2 ze*hy7ce6zyeroom of length 6.5 m, width 3.1 m, and height 2. hz(2dy9czvun 73dy0 l6c* nye*3x eme5 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 aboupiiodj iv8mj+ -j5e39 t 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 techniques isnlh;-ko 6 4.isj g1soq abo qi n-hgk4.jo los61;sut $10^{-12} N/m^2$ 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 5.5 L when 10 m beu. .sg kelrse;varso 9rx); *6low the surface, to what volum.skrslag e9r )*vurse;o; 6.xe would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon bjl(f-ufjjyd7r *c;wa3; q e 0enters 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 must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentr0ecld 7(aqf ;fj- w3bu *jj;ryy.)    K

  The temperature of an ideal gas is ifk) g-rx,rzv.ei:u i60g eq2hncreased 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 ofdt b*l j8a6il h1-,ya h;jqk ao)nv9l, 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 surface of the Ean3m;i/yixuo vh4 7c6m rth, estimate the total number of air molecules in47 c vm3o;my/uhix6ni the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molemj+f4hm74. )pvj v8lptyvydk6t;8e z cules contained in a 7.6$-m^3$ volume at 4.2 atm if the total amount of nitrogen is 1800 mol?    m/s

  A standard cylinder of oxygen used in a hospital has gauge pressure k tw--2mqk,pb4ofd0z = 2000 psi (13,800 kPa)zqfp, kd -2o0wmtb-4k 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 mel:jarsjd9i,s. j f ;9mrcury 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 gasolinmqpyss+11v 9-j xhqi*wck+a8l3j d6me 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 snu2g.yn/lre;yu( 9vcna gly around the 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 onto a g9n) g3r aq6diilass 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, adopl c,nc tfms3r wt zf 6*nq1/a8p,)c8zzted 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 ch6 nn9d*x6cahdg8eqw d 7u6 e/jarged, 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 Ear9t)g v:i4wvwx j :dz-qth 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 susa.+/tohdi6cx dq8 /eipended against gravity by tennis balls 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 are thi+/aoqc.h 8ei/dx6td rown at 12m/s   balls/s

  A scuba diver releases a 3.00-cm-diameter (spherical) bubbuz if2 6)og7 et4 *a-tjn9ggxssz-m .wle of air from a depth of 14.0 m in a lake. Assume the tempezs-t.gu)6 w sz4a*t9fog7inm- x2gj erature 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 following twp6qr)6beqvhfd/d +o,svgp8 *o days: f bh/d),vrd g8qqs6o6p+* vpe
(a) a hot summer day, with the temperature 30$^{\circ} $C and the relative humidity at 40%;    Pa
(b) a cold winter day, with the temperature 5$^{\circ} $C and the relative humidity at 80%.    Pa

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

  Estimate the percent difference in the density of iron at STP, aku 4pdq rg7 upu6s4xg6n3w;r3 nd when it is a solid deep in the Earth w3dw6kurgu4q 7g4u; nrp3 s p6xhere 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 th(:vt3fgr ni :iat, for an ideal gas at constant pressure, the coefficient of volume expansion is equa3rvt(i f:g :inl to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, people constantly dehumidify their ( 3j 4,qmz:lisshp . nxdwovvz7o/) ,vcellars to prevent rot and mildew. If the cellar in a house (kept at4no:vx)m(, vsih zw37plzso j., dqv / 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