Which has more atoms: 1 kg of iron or 1 kg of aluminum? See the periodic table oraq,7)mnw, nn; + h xt0wp7pvrr Atw;rm apn,h,vp7qn n7 r0+x )wppendix B.

Name several properties of maty)(*br0hd8y if i (lrxq :eqfp,l0p,u erials that could be exploited to make a thermomet qf0i xf u8 qblrly(y,ped0i:)hp(,*rer.

Which is larger, 1 Ca4xm eqlp305l wk(h 5b $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermallkgvp(vq1 ,r + equilibrium with system B, but B is not in thermal equilibrium with system C, what can you say about the tempe rk,vvpg1ql +(ratures of A, B, and C?

A flat bimetallic strip consists g7vy9 lsk6wo9 of aluminum riveted to a strip of iron. When heated, the strip will bend. Which metakw6gv9 o7l 9syl will be on the outside of the curve? [Hint: See Table 13–1.] Why?

In the relation $\Delta$L = $\alpha$ $L_0$ $\Delta$T, should $L_0$ be the initial length, the final length, or does it matter? Explain.

The units for the cos5w m;mxyao;pxv;x) i97avnp 3ly 9f,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 simple thermostat used to contrfq kn74w ,9bqxol a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bondefxqq9bkn 7 4w,d together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls the furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at t gmf2,s28hgduq4s 3pmhe ends often have a section in the shape of a U.823sgpf4h,u md2m sqg Why?

A flat, uniform cylinder of lead floatgk8bitkpg4 xb5 )y f,+-(pexn s 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 th lx7h2+px)),qj dumo jermometer is first placed in a hot tub of water, the mercury initially descen)jodhj+7m)x pl,xuq2ds a bit and then rises. Explain.

A glass container may break if one part of it is heated orn8nc( wx8yt7+bawq(k(tnm8 w cooled more rapidly than ad bn(88mwnt y 8tnwx+ac(qk7w( jacent parts. Explain.

The principal virtue of Pyrex glass is that i8 f+4 ;6ucq ehxgvuave+ ;0e ,kzs,nrets coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of cn+svkeaev8u ;+;r,4 g,e h6u qexf0zPyrex.

Will a grandfather clock, accurate at 20 5vdsq1q(7a l,wjurh2 $^{\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 bottom and top to bul jp cqei)ub4*la73s0c6fax7 8y zmj f4ge so badly the can will not stand up.by6 cez30j8cql*afm7ju pix74s )4f a What has happened?

When a gas is rapidly compress7iajfi6v9, , 6 ykyhlped (say, by pushing down a piston), 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 hapvlih,9,y6 6yai7 j pkfpens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminth3as0s1e0afp h6tv ,um sphere submerged in water increase or decreasetah te 3shvs, 6af100p if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law fodt1(c*wj )tou llows from kinetic theory and the relation between average kinetic energy and thetdjc*u tw)(o1 absolute temperature.

Explain in words how Gay-Lussac’s law follows from kinetic theoryn wb0. 3ply6;78acaggc+ ud7f fa(dj b.

As you go higher in the Earth’s atmosphere, (qvnzp+0uoy, the ratio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum speed an object must bfrcb +8pg1 asf0rd (ck) l(yxom7/ 4chave to leave the Earth and never retu/+ o8(dcc7g 0cly(4rp fxb kb)1amsrfrn. 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 atmosphere.

Alcohol evaporates more quickly than water at room tj)9ys w((wo*bhk7 igdemperature. What can you infer about the s(ik)g9* (7ybo wdhwjmolecular properties of one relative to the other?

Explain why a hot humid day is far more uncomfortablv6*: vkct3 -webuvayxt n52r 9e than a hot dry day at the same temperatutvt wb:rx3a- vv6ec2k *5 nyu9re.

Is it possible to boil water at x) bm4;h3 ddgio/xj+proom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature is 0*v3xudmym :zthe same but the humidity is different. Which is more dense, the * yvm:dx0m3 zudry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an o4npyuwefd2u 9 t((e.4wmpk,hiiu o2/verheated automobile twum/py 9 noi2eh(d,u 4e24pi(fk u.wengine.

Why does exhaled air appear as a little white cloud in the winter (Fig. 1c 2ysgcs 5ps nt2wr0vj.ns30:3–28)?

  How many atoms are there 5h2 gg*+lkjh hin a 3.4-gram copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold r/b; ua/lj-ce .yz 9hyhrv80pd ing compare to the number in a silver ring of the same;/ d-/py0uc h98aylevrj h z.b mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken tos0its15)j.8 5cvod ge q il/nb be 68°F. What is this on the Celsius scale?5b)s 8ci5i no 1lg.ve0sjqt/d   $^{\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 recorded are r(fhs7 ewckdq2*.9jw 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

  (a) 15 $^{\circ} $ below zero on the Celsius scale is what Fahrenheit temperature?    $^{\circ} $ F
(b) 15 $^{\circ} $ below zero on the Fahrenheit scale is what Celsius temperature?   $^{\circ} $ C

  In an alcohol-in-glass thermometer, the alcohol column has length 11.82 cpr-uu 8r: j-e5mecto+m at 0.8p tr or5:ej-mu+-ue c0 $^{\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 long (20 (ad1s;xd2q l 7gt rhq9$^{\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) /nqqrdmr7we mv4 5o8 wrought iron approximately 300 m tall. Estimate how much its height changes between July (average qe)n4qwr57o/vmr8d mtemperature 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 x:d4tja8b(l )fqo 8qlp z;y.oare larger than the rivet hole are often used and the rivet is cooled (usually in dry ice) before it is placed in the holeoz8a4pyqdltj q 8: . b;xo)fl(. 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 water5,m qlo/tdxm + at 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cxvfp9t el67t jie2kv/t9;we. m in diameter. What will be its change in volume if it x 69;j29tw letfei/pv.7tekv is heated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 m -t. xmvd,fasfyy/o 7-L of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of water qlqdzz xbh7 jd9 ozc1c5ar:):p.w +r5at 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 hi*ttl4 an n(0p5f,jr:uc /lviron. 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 veshmkt; 2q 0 v6 ru.n)81ykwsblpsel so it can expand in essentially one direc.6p;r2uhqvkym )lnt s8 01wbk tion only, show that the effective coefficient of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change ibtzw7xyw6c p1u8u 3 8dn the density $\rho$ of a substance, when the temperature changes by $\Delta$T is given by $\rho$ = -$\beta$$\rho$$\Delta$T
(b) What is the fractional change in density of a lead sphere whose temperature decreases from 25 $^{\circ} $ C to -40 $^{\circ} $ C？

A uniform rectangular /x70ec sx4t 8h /ueqghplate of length l and width w has coefficient of linear expanshe c/t exq/8xs4hg 07uion $\alpha$ 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 set7: usn97pq)f d5jqa 8,frvygcik:6olid, $\beta$ = 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 timx4k (emf8zg*0s s9hp0gn+ d8 id4in2jidps:k e at 17 i4es( 89n0 kfg0s : ixs8*hp +2gzi4npmdjdkd$^{\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 77ig b ,2lvuveof 0.140 mm. The bulb has a volume e,vgv7 l2u7ib 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 vni- u(2eb nq;is rotating about its axle on frictionless bearings with angular veln b2-;e(nivu qocity $\omega$ = 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 whet+l. s, t6gl:j(muczgn at 15°C. How much stress is required to keep it at this length it6zg.llc ug (+ jmts,:f the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-b5y;zdh z a+8wfeam 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 134.122.07zp1vvik3hov2;c ns0n b/d rlfj,j cm 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)r0rm0of;76lrx m yot 7 yyyk, 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 temperatur hx vv -yud2mg,gr)t61e on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior of the Earth and i:y-i57c v(amk a 7sloglb7h(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 combus1h91w knoog/xp . l2fm6wb, l6wxoc0ction engine, air at atmospheric pressure and a temperature of abou6.1 9 lwxgclopbm n/6k w,xh2w1oocf0t 20$^{\circ} $C is compressed in the cylinder by a piston to $\frac{1}{9}$ of its original volume (compression ratio = 9.0). Estimate the temperature of the compressed air, assuming the pressure reaches 40 atm.    $^{\circ} $ C

  Calculate the density of oxygen at STP usvd uk1s4 s*qfrf(;ac)ing the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nimb,yglffoio*k ;-. 7u trogen ($N_2$) 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 contaipbup1 nr. )u3lns 18.5 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 m/ nasl*wd .ebber;+5 10.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L container holding 1054 ap., ai3t bvjrccf,1.0 kg of argon gas at 385 K jc3aacv ,,4ftpir1b .?   $ \times10^{ 8}$Pa

  A tank contains 26.0 k8kxc ou+u inln) 2a.*vg of $O_2$ gas at a gauge pressure of 8.70 atm. If the oxygen is replaced by helium, how many kilograms of the latter will be needed to produce a gauge pressure of 7.00 atm?    kg He

  A hot-air balloon achieves its buoyant lift by heaqz68s: f 3+hxf-mvn-vpmu vfu8dts9 m :/meg*ting the air inside the balloon, which makes it less dmt8 9f-g 38 6hvm-numfu+ mx/s :de vz*f:qvspense than the air outside. Suppose the volume of a balloon is 1800 $m^3$ and the required lift is 2700 N (rough estimate of the weight of the equipment and passenger). Calculate the temperature of the air inside the balloon which will produce the required lift. Assume that the outside air temperature is 0 $^{\circ} $ C and that air is an ideal gas under these conditions. What factors limit the maximum altitude attainable by this method for a given load? (Neglect variables like wind.) $\approx$    $^{\circ} $ C(Round to the nearest integer)

  A tire is filled with air 1(y k64( ddlptz3snmuat 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 18 5r5uyic5r)r,v 7 jvxe.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 escap0, tk gix rrhgih azlo57;p,u1,za v0*es a child’s hand at sea level and 20.0 $^{\circ} $ C. When it reaches an altitude of 3000 m, where the temperature is 5.0 $^{\circ} $ C and the pressure is only 0.70 atm, how will its volume compare to that at sea level?    times the original volume

  Calculate the number of ma9djuf* e-xwwsvwg2s 0vw 0vq-w (u9:olecules / $m^3$ 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?zp55k jofot p b0)he7:    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) moles, zjjrfs +7n jc25e lfuz 66fx30   $ \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 99 p5 hjxapty;lx82mh5.1$ \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 yiu , nsv t2m(y +fq;dgfnz-/r)omvj+sr6gt;9ou inhale that were also in the last breath Galileo took. [Hint: Assume the atmosphery;t ov/ -6,nggsi) +t j9n+m;qr(vu2zs r fmfde is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the aver qu1rso n2l3*s )jm(jyage translational kinetic energy of an oxygen molecule at STPs y rnu13j(l)oj2msq*?    $ \times10^{-21 }$ J
(b) What is the total translational kinetic energy of 2.0 mol of $O_2$ molecules at 20 $^{\circ} $ C?   $ \times10^{3 }$ J

  Calculate the rms speed of helium atoms near the surface of the Sunj1h/q 8/yv dux u9s;qsm gk7(n at a temperatg/uh;u m(9s1qd njy7/k8q s vxure of about 6000 K.    m/s

  By what factor will the rms speed of gas mt/bxyq+30yb +ut m)v- bdfuv9zxz)6 jolecules increase if the temperature is increased fv -6 q x yub)b) 9z3/0d+vf+tzuytxjmbrom 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 infpk.f;9g+1q)4 jjdep zp ygm9 units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8. Calculate the rms spej.e)m9 1pdgzyp pf+gfqk;j 94ed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas at 20.0 +m 2)mh;4s(jaufh , 3aaxh n ggr;-epn$^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a ga,d x(bhc t-7vxk88xk ys is doubled while its volume is held constant, by what factor doexdt7b8,h (x- cx8k vyks $v_{rms}$ change?   

Show that the rms spee+m3wu sm4a1 rgd of molecules in a gas is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two 7 grci.o/pg)xgases at the same temperature, the ratio of their rms speeds is equal to the inverse ratio of pr/gi ) 7cgo.xthe square roots of their molecular masses.

  What is the rms speed of nitrogee9wxbwke-/ ( p1cbi.9os7qb. nre5 ymn 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 5ek+8*0 kyx )g- )jmrijed n.aw9gmsl 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 between nitrogen moleculesywc* mem,6 dt*mko *w vu*8;ep at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whose molecular mass is 89 u in a l5ecu0az/g m6 bivingag6cb05mu/ e z cell at 37 $^{\circ} $ C.    m/s
(b) What would be the rms speed of a protein of molecular mass 50,000 u at 37 $^{\circ} $ C?    m/s

Show that the pressurla rz0e/ /d+ ouj6 um;kx-bwzj8 u7p7te P of a gas can be written P = $\frac(1)(3)\rho v^2$ where $\rho$ is the density of the gas and v is the rms speed of the molecules.

  The two isotopes of uranium, cwn)09lfa k 3ks by9b)$^{235}$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 pressufnizm t(4mk9ru(o3 o 7re, in what phases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the press ( n,8ldbjyyff:f nhr)a0a54 oure is 0.01 atm and the temperature is (a) 9f yfjbh8(4na 0:)5,n oaylfrd0 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (approximately) if the humidity is 50% on a day when theq :.mw,yzc y7x temperature is 2zw,. xycq7 m:y5 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure0 t*cen 51 gndbhqi1h7 at a place where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure at a particular place in the mountains is 0.72 atm, 7,-:f5sesq9i ;l dxpjg- lfp sestimate the te97,df5sfssel-i pq g-l:x;p jmperature at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water26xd ddlb)q2x1/ jax n is 530 Pa and the relative humidity is 4xq2 ad/ ldj xdnb162)x0%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of water on a day when th5;b*o gu r:ne/sp p1cwe temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside ai*:h,1y oiacvn2i.j o h3ma7l pressure cooker if the water is boiling at oa1i7:2invaj m3 .,yh*hlcioa 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 lk66k- gw abpn.u-i4xroom 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 zhgzmjaan3em 5/6 f*1ew 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 Tasn as g4oh m 1h0blgp4kaacl-96ej:+1ble 13–4) to diffuse a distan c6 ms4sh0aa+:1lbhlk- 4ap9e g1 ogjnce 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 tzyw0o m5/0c gvdsqjyf:4:m*l hrough tiny tubes called tracheae. An average trachea is abys/m*my dzlgf q:0wc0j5ov4: out 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 been calibratea 4 );chg0an4)syz 8j.bharkb d at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has been z02+ik8riqmp00yd dm 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 topk,p.anfe td.j l(h63p. z iop-4fv90ibh ,hemperature. How much error will be made in a recipe calling for 300 mL of cool water,f,kdoh(zvj 0p6.i9htibh . pp.,n4 o -epa 3lf 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 heliumz8 oo3gipz3s sj m3o 9z356beq gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased t6oi 9b8oz3gzm os3 q5z3e3sjpo 5 atm. What fraction of the original gas remains in the cylinder?   

  Estimate the number of air molecules in a 0zzltbv ;1sd:x .obl)room of length 6.5 m, width 3.1 m, and 0bzt.:sl; b1ovxl) zd height 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 densib8v)mm com:. bty of 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 vyb5.x.*)i6fwv8g v ld a zs-sgacuum techniques is abouv.g yg iavs d6-zx)b s.*wl5f8t $10^{-12} N/m^2$ 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 below the sp9dq,odg ph(nc it:kr(,: 1llurface, to whai( t1,rdl,hk: p9c:pdn qlgo(t volume would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon ente.p2ysh:wqvil(xa7 2wh a n20ors 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; innyisw( x wpv20 .oha7:2a l2qhdeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of an ideal gas is increasebrq r5rnw99wdarunn1b0 fg:;l 2 2hi4d from 110$^{\circ} $C to 360$^{\circ} $C while the volume and the number of moles stay constant. By what factor does the pressure change? By what factor does $v_{rms}$ change?$\frac{P_2}{P_1}$ =    $\frac{(v_{rms})_2}{(v_{rms})_1}$ =   

  A house has a volume of 78b1ev5 cewuejk 2y: /g70m$^2$ (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 atartmi289gcdv d s-2*d the surface of the Earth, estimate the total number of air molecul-g2vd t c8s*r92addi mes in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules connro(diq )5zr9:n 3swgtained 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 8 2t pu6jprisw6p p a11;w2vimhas gauge pressure = 2000 psi (13,800 kPa) and at T = 259K How long will the cylinder lp6 piv 2pa2sj1;r6w1 i8u mwptast 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 mercuryg2v:: ,szfukc 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 gasoli0h 1l zi )zzg:h/lfudv6u7a +ru,h)ckne 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 at 25j o0 9oz*.pyjild7up)$^{\circ} $C, but then was heated to 45$^{\circ} $C, how high above the Earth would the band be (assume equal everywhere)?    m

  A brass lid screws tightly onto a glass jar a)8lzs 0n uh44s0 qwlxfn. oet8t 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopted in the 18zt,6fh ;43k g4hnljuj$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, has a pressure of 195 atm a*baxem cr/94 yt 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 froqfjy7g9 pn* zg)j4b8gm the 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 suspended v1 n-t+ 0(esjt4hr+ c;towfecagainst gravity by tennis balls thrown vertically upward at it. How many tennis balls per second must rebct-tjf+ o;r14 wc +e(enth0svound from the lid elastically, assuming they have a mass of 0.060 kg and are thrown at 12m/s   balls/s

  A scuba diver releases gkym59 l4vg.za 3.00-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas.45 y.lk 9mvzgg How large is the bubble when it reaches the surface?    cm

  Calculate the total water65*pgq1mw-t.6l tafkl5 qk qot94 wyt vapor pressure in the air on the following two days: - 5 qq*fmk619aowttwlytgt 5q k.lp46
(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, and when it is afrp/27q8lq1s03 xywla bz :kw solid deep in the Earth where the temperature q 3rlp/ z:sfqk10a28bxwwl7y 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 s*2(+(idb)ptna fht*e +nwtss how that, for an ideal gas at constant pressure, the coefficient of volume expansion is equal tohas(tp(is+tt d*e2 n* nfwb+) $\beta$ = 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 .(6-a/u h6,nsco d,me zbfyetcellars to prevent rot and mildew. If the cellar in a house (kept at 2/d oy(-,c6b .f ,mezane6htus 0$^{\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