Which has more atoms: 1 kg of iron or 1 kg of alum54;7slo jim ld1d 8ojninum? See the periodic table or Appendix B7joso j ;d1llnimd8 45.

Name several properties of materials that could be exploited to make a t yhnuzf9v4 wu ;/,1:snbxfz)-,wafs q hermometeu ),; z nb1 f4wuns fzxw:s,/-fyhav9qr.

Which is larger, 1 C eu ze,v7ct/h, $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in ther dgbkm(c1b -mqu7 9ww.mal equilibriumudm-gw1 c bkm7bwq( .9 with system C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted to a strip of iron. When d5we9 ,4gok txlman.+heated, the strip will bend. Which metal will be on the outside of the curve? [Hint: S.adm +xkw5,9l n o4tegee Table 13–1.] Why?

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

The units for the coefficient of linear ec (g4 u2vphzg-xpansion $\alpha$ 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 control 1-l xy5f br8m3x y)rlha furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. The electric switch is a glass vessel containing liquid mercury that conducts electricity when it can flow to touch both contact wires. Explain how this device controls t8x rhyf53rm blxy )-1lhe furnace and how it can be set at different temperatures.

Long steam pipes that are fixed at 4ka :fkrlfb 9,ty* 6oophdn/ tkr .8e4the ends often have a section in the shape of 4kob d, :.6k8/h kp9rnf toftly r*ae4a U. Why?

A flat, uniform cylinder zb 34pu ;a jopz8x:n-rgjk- 0xof 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 placed in a hot tub of wat pa u;kg pv7ink;h130xer, the mp 0nu7ax; gkhkp3;vi1ercury initially descends a bit and then rises. Explain.

A glass container may break if one part of it is he 1mtb.enz7s t)ated or cooled more rapidly than ade .m s7b1)ttnzjacent parts. Explain.

The principal virtue of P r(x5 zaxf49vjyrex glass is that its coefficient of linear expansion is much smaller than that for ordinary glass (Table 13–1). Explain why this gives rise to the inf5x v9rzx a4j(creased heat resistance of Pyrex.

Will a grandfather clock, accurl k945utm1kdw(mzkp+ 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 cause its bottowm8i312ot p uim and top to bulge so badly the can will not stan81pmuoi2i w t3d up. What has happened?

When a gas is rapidly compressed (say, tnf;l /uv y37y uj8u*yby pushing down a piston), its temperature increases. When a gas expands against a piston, it cools. y3fj; n*/y8ylut uu7vExplain these changes in temperature using the kinetic theory, in particular noting what happens to the momentum of molecules when they strike the moving piston.

Will the buoyant force on an aluminum spher 9xe (kpx t3yb5vwkzi8bnl39;e submerged in water increase or decrea3zxnwkvpk9 9(5 i3yx8e tbb;lse if the temperature is increased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how bs( w9d9.goui Charles’s law follows from kinetic theory and the relation between average kinetic energy (dg.w9u s bo9iand the absolute temperature.

Explain in words how Gay-Lussac’s law follows from ki 1cxkqzpl*v/2 netic theory.

As you go higher in the Earth’s atmosphere, the raogodby 4b-rq3 y) m,a/tio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Earth refers to the minimum spee 8;ztc*u6jo sgd an object must have to leave the Earth and never return. The escape velocity for the Moon is about ons86u j;gzto *ce-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 temperature. Wh;2fwkw-y.6y tc mewf6 at can you infer about the molecular prope ty6y ;.ffkwmw-cw6 e2rties of one relative to the other?

Explain why a hot humi ve kb8:puci74d day is far more uncomfortable than a hot dry day at the same tempp:i 8vk4bu c7eerature.

Is it possible to boil waterdz 0bu8ia*1y v9kd ak. 3gsv;b at room temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air podtae m19l57temperature is the same but the humidity is different. Which is more dense, the dry air or the humid air at p1l7e5 9t moadthe same T? Explain.

Explain why it is dangerous to open the r*eqo0rsq.+z t adiator cap of an overheated automobile 0+zter.s qqo* engine.

Why does exhaled air appear as a little white cloud in the winter (Fig. 13–auc q.:btg,2h 28)?

  How many atoms are there in a 3.4-gra a44u zu7f7m gunl: ofaoc43u*m copper penny?   $ \times10^{22}$ atoms of Cu

  How does the number of atoms in a 26.5-gram gold ring compare to the numbe 2n md b,7li3;ppey4p8 fal9smr in a silver ring of thmin;la8l p,7bmp2 df 9ps4ey3e same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is of 7/h1n9amveydloi1 rl * d1sq-ten taken to be 68°F. What is this on the Celsius scale?m1d9lsn lv-iry1 o/1ah 7ed *q   $^{\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 temperatsu+yab.78ya/y zp w;nures recorded are 136 $^{\circ} $F in the Libyan desert and -129 $^{\circ} $F in Antarctica. What are these temperatures on the Celsius scale?high =    $^{\circ} $ C
low =    $^{\circ} $ C

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

  In an alcohol-in-glass thermometer, the alcohol column has len7ce0p qy; z1nbgth 11.82 cm at 0.q; p 0bye7cn1z0 $^{\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 mr1z by9qp .j8m 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.5d(l2:(zxt0r rpr sor 13–29) is built of wrought iron approximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and January(sz2r:0 5(potrxrr ld (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 thrb7ey3 oztf*t5g j0 n.a *w ui7-3cfzsan the rivet hole are often used and the rivet is cooled (us at u3*s7jcrfwftn3.5e7 i-yz zgo*b0ually 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 v(d95dvnt ,t rnk5njoian1xs e-* x: 1at 4 $^{\circ} $ C is $ 1\times10^{3 }kg/m^3$ What is water’s density at 94 $^{\circ} $ C?    kg/$m^3$

  A quartz sphere is 8.75 cm in diameter. What will be its change in volume if 7 (h ,*:gwvypwc9:nbdkcos*y it is :vhw7y:,y(wdc9nsop* gk c*b heated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with q cgm2dy4 a,5d350.0 mL of water at 100.0$^{\circ} $ C. If the temperature decreased to 20.0 $^{\circ} $ C, how much water could be added to the glass?    mL

  It is observed that 55.50 mL of water at 20 ec-3z2aub gcciw)9nd -6r9d k$^{\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 tvgyfv 0/w3ptjv7y 4w1o be placed in a ring made of iron. At 20 $^{\circ} $ C, the diameter of the plug is 8.753 cm and that of the inside of the ring is 8.743 cm. They must both be brought to what common temperature in order to fit?    $^{\circ} $ C
(b) What if the plug were iron and the ring brass?    $^{\circ} $ C

If a fluid is contained in a long, (of2z .fdvye 09nbb: bnarrow vessel so it can expand in essentially one direction only, show that the effective coefficient of linearbfvb .n:(z od29yb0fe expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change in the de */h8olidh ;l mhhod94nsity $\rho$ 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+09l+ bwfts:dy :*7 +zxvtbmff.hm er width w has coefficient of linear expas:f+b wb7+m:yt r.+ dlefh fztv90m*xnsion $\alpha$ 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 1 rcu9x ,r bvskr k1;r+6dare9solid, $\beta$ = 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 mah z;vla6:;bzs x7x3po de of brass and keeps perfect time at 17 ;zbpov3; sz: xa6x l7h$^{\circ} $ C. How much time is gained or lost in a year if the clock is kept at 25 $^{\circ} $ C? (Assume the frequency dependence on length for a simple pendulum applies.)$\approx$    min(Round to the nearest integer)

  (a) The tube of a mercury thermometer has an inside diameter of 0.140 mm. T*d2su f(+eb6soof 2 uc; h4mmshe bulb has a volume of 0*2 (m6 hufe osub;d4fossc2m +.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 cylindricadef.5+fuufv 1l wheel of radius 0.41 m is rotating about its axle on frictionless bearinfd 5f1 uvfe.u+gs 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 much st 1tqe+3zgle4t:p tl; rress is required to keep it at this lenzql3; epgt:r le+t 41tgth if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of crosjx9cadu+- 9 luw-dte*s-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 pmdn *9,e1j:gch .x-6jwlp rrcm 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 temper (.0vdjvm:dzctv1e)s+e, qa satures on the Kelvin scale:
(a) 86$^{\circ} $ C,    K
(b) 78$^{\circ} $F,    K
(c) -100$^{\circ} $C    K
(d) 5500°C,    K
(e) -459$^{\circ} $F    K

  Absolute zero is what temperature on the Fahrens x(fy1sfl3 vz0udkmgu96-+ eheit scale?    $^{\circ} $ F

  Typical temperatures in the interior o 5lo+)c/qbqwen0 my7zf the Earth and Sun are about 4000$^{\circ} $ C and $ \times10^{6 }$ $^{\circ} $ C respectively.
(a) What are these temperatures in kelvins?    K    $ \times10^{ 6}$K
(b) What percent error is made in each case if a person forgets to change $^{\circ} $ C to K? $\approx$    %(Round to the nearest integer) $\approx$    %(Round to three decimal places)

  If 3 $m^2$ of a gas initially at STP is placed under a pressure of 3.20 atm, the temperature of the gas rises to 38.0$^{\circ} $ C. What is the volume?    $m^3$

  In an internal combustion engine, air at atmospheric pressure andz;ts + m,8gpfo a temperature of;z og+ f8,mtps 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 STP usinspo4*ozig;/ vtu5 z5 zg the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 kg of nib mj0afpp2 rdkw6p0ebn +* 58hzfwm9te2y2c 0trogen ($N_2$) 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 kg of nitro;0mwr,o , gjg0in.kg xgen ($N_2$)
(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 isg 3(h,dwzc(6ykf gqn7/ bl6 wh 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 3 w:m dgz7ojaam p+u;-;5.0-L container holding 105.0 kg of argon gas at 38:odgwama; 7u ;m+zp j-5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 vpdz t4 73+xiuvl1f,uzkuz/6 kg 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 heating the air insidle;2bs--isw d e the balloon, which makes el is-b;-d s2wit less dense 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 ay2ywn p/udm 4ux:.s; xt 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 15l s )4m+lbo7qvc g1ah8.0 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand pp.tgd*,emeq 8rqs*p qz* gk.5px2i* 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 molecule-xgs; +a4 ik8 xw0yyebs / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many.y/e t ;nk/ky;2ogt t0 +7pgb6ojewie molecules?    mol    $ \times10^{25 }$ molecules

  Estimate the number of (a) mol;oe ,rt,w5 zec;dz9txes,    $ \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 na y3t1( vd7 no4t ca(j:.sgps5.1$ \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 l+jh*x8tj7 x t2.0-L breath you inhale that were also in the last breath Galileo took. [Hint: Assume the atm+tj7xl8 txjh* osphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translational kinetic energy of an oxygen moleh3z.k8k;j9hgnwhcm .cule at STP? hj. k;hcg8 9zwk3h. nm   $ \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 2yao)py r /cc 5tz-i9fp i/bs(near the surface of the Sun at a temperature of a c-bip/) yy2o5ztrc9f psi/( about 6000 K.    m/s

  By what factor will the rms speed of gas mge*t 7 ,wz9nq0hzs0fsolecules increase if the temperature is increased0q,sw9en zszht* f0g7 from 0 $^{\circ} $ C to 100 $^{\circ} $ C?   

  A gas is at 20 $^{\circ} $ C. To what temperature must it be raised to double the rms speed of its molecules?    $^{\circ} $ C

  Twelve molecules have ta2w9 wg kk0syzv( p:k9j2kxk8okg7)j he following speeds, given in units of km/s: 6, 2, 4, 6, 0,:)9vg 8kko7 2ka90pwk(zkjw ysk2gxj 4, 1, 8, 5, 3, 7, and 8. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of moleculvm q+/i)vhn7 xes in a gas at 20.0 $^{\circ} $ C is to be increased by 1.0%. To what temperature must it be raised?    $^{\circ} $ C

  If the pressure of a gas is doubled while its volume is held constant, by what fn4 x4 (y*hkun11tx crl 0lqyf2actor d(r21ylnu4k q yx1* ln0x4ch tfoes $v_{rms}$ change?   

Show that the rms speed of molecules in a gas r.0ot2 xzsx- ljz09j.s dy5wyis 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 tf-9tz 9 et0jkche same temperature, the ratio of their rms speeds is k fe-9jctz09 tequal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrogen molvn p6z: tlh;7hecules 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 molecuu886aj v ) kysbka6*zule 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 dv6 pi q9mzep ucz5.2;kistance between nitrogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acbcig+5a hkh3p; - 1oa(37kw g lzkyqig*+ik7bid whose molecular mass is 89 u in a living celag- wl 3kpc7i3oaq bh+kk zh1i;i*gby +k75(gl 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 ga (yfhi.ed1g/) :azjbxs 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,hxjfwd4 4m,gh 3.v8xc $^{235}$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 pressurvof 2eon ru 31xlm6 vc-1(kqx1e, 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 whb:nyey3gm rh 4 ir6)m7en the pressure is 0.01 atm and the temperature is (a) ryh7ni6)m3 eb r4yg:m90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point (appr gs mklaq61v2jd.yowh25ek (5oximately) if the humidity is 50% on a day when the temperatu2. sw6d2g1eoqk(vh5 kjla my5re is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a place whx032u5h:ai9h o tf guec5 dw5pere water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure (sj/ b.avmaxt2k7 ye fag61q 1at a particular place in the mountains is 0.72 atm, estimate the tempera 6vyf.1egxkatmas qb(2/1 ja7ture at which water boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of water is 5-u;aaqyw3x) z30 Pa and the relative humidity is 4 xuaq-az 3);yw0%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure of watns;2g p fz* 0;fhv:ydjer on a day when the temperature is 25 $^{\circ} $ C and the relative humidity is 35%?    Pa

  What is the approximate pressure inside a pressure cooker if the wq( pg1pw: -1lfpsc mbq/y3 a0gater is boiling wgfg(qp1l-q y3mpa / pc0s1:b at 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 volum6p1t+b ,hcu pp)moa4 je 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 l(nb cz+i7i cl 8)uoa;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 a -m qrv8;x6tdmolecule (see Table 13–4) to diffuse a distm8qta v-6;dxr ance 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 tqojk-/h , 1 0ddu/xdlt it)hcfl 4iz*.hrough tiny tubes called tracheae. An average trachea is about 2 mm lo),ozld t uc*hjf10/x 4 diiqdh-/ t.lkng 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 h+80 y4abq z/toq4 eucvas been calibrated at 20$^{\circ} $C. At 34$^{\circ} $C,
(a) will it read high or low,
(b) what will be the percentage error?    $ \times10^{-4 }$ %

  A precise steel tape measure has been eg 0stm4- j/qhcalibrated 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 atja qvf1nnru2s3- -fa+d i2f+t normal room temperature. How much error will be made in a recipe calling for 300 mL of cool water, if the water and the cup arf-i2qf 2fvtn 3ja1surnd++ - ae 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. After many by22 x7a . egkxr/btb-calloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas rem ygt-.b22xa/7 bre xckains in the cylinder?   

  Estimate the number of air molecules in a room of length 6.5 m, width 3.(md/d+ wjyx:s 1 m, and height 2.5 m. Assume thesx: /j( +ymwdd temperature is 22$^{\circ} $C. How many moles does that correspond to?    $\times10^{27 }$ molecules    moles

  In outer space the density of matter is about one3( c5klxoeeg 0g1nb zlsp(65vm.m3 qg 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 a *nf702 mar8dza*d/e7t xx lcdvailable vacuum techniques is about m2**80ca/taf xd 77nedxd zlr$10^{-12} N/m^2$ 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 x-mk243 ldyr1tq:s hl m below the surface, to what volume would his lungs expand if he quickly rose to tt2rhqmx1 lysk3 d:l-4he surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmosphere a6 gl+ - edvu4og9 0suoer q;k2q-yt7uzt 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 ofs;6 2gqlu-e kteyrgu7vuq09o -4o d+z 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 a 1jj.r ci ip3efv+gud1:8a ,kis 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 of df1nq(ewr 8 9u770m$^2$ (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 surface4l*fc/f zu su9 of the Earth, estimate the total number of air moz *s94ucfl /uflecules in the Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen molecules cont0,9upx 8k y w2f8aremfained 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 press9d/; 12bzkgj rsx( fvoure = 2000 psi (13,800 kPa) and at T =vb2oz(xrdsj ; 91 fkg/ 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 mercury h h+sk h ;(x4-ag5ywpdat 0$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline rl.sg4hjye2i /d/o p 8at 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 es s,s0 lgdbhi654 xpc5 qao+i)ey3j0nquator 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 tightlq/yg p3mdrg;xwyy.c:qm0 n o)x9q .v8y onto a glass jar at 20$^{\circ} $C. To help open the jar, it can be placed into a bath of hot water. After this treatment, the temperatures of the lid and the jar are both 60$^{\circ} $C. The inside diameter of the lid is 8.0 cm at 20$^{\circ} $C. Find the size of the gap (difference in radius) that develops by this procedure.    cm

  The first length standard, adopted in thekdee-45hr axadj o9 :-me /mv4 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 fulkj;2x8giny w/ ob8jv-.)qct lly charged, 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 theco (kklj07 (p t*lv3+8d.5 x:srr5ivghv wfv t 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 suspenw 6lm*mlozn hlntq64cdv 19lg-wb/ - 5ded against gravity by tennis balls thrown vertically upward at it. How many tennis balls per second must rebound from the lid elastically, assuming they 4h l lvzc-ngq ll/ 5mbw6tmw-6d1 on*9have 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 depthv8cep()0 6bi;qjsots of 14.0 m in a lake. Assume the temperature is constant at 298 K, and the air behaves as a perfect gas. How to(bqi 8s ;sc06) pvejlarge is the bubble when it reaches the surface?    cm

  Calculate the total water vapor pressure in the air oncgc( y aql1.4m the following two days: 1gl(m.yqcc4 a
(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 d vj o9c5lgeno3 e01.nmensity of iron at STP, and when it is a solid deep in the Earth where the temperature ileejo 9.m30non 5cgv1s 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, fo;qny 0chk ekzc6; (h3nr an ideal gas at constant pressure, the coefficient of volume expansion is equal tcqn kh 6hkzy30e(n; c;o $\beta$ = 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 ce(io8r5n6 y4xq8iknvmllars to prevent rot and mildew. n i5(x88qrik no4mv 6yIf the cellar in a house (kept at 20$^{\circ} $C) has 95 $m^2$ of floor space and a ceiling height of 2.8 m, what is the mass of water that must be removed from it to drop the humidity from 95% to a more reasonable 30%?    kg