Which has more atoms: 1 kg of iron or 1 kg of aluminum?0h+vl7wx-+c clwv m/z See the periodic table or Appendix 7cl+vh w-mc/+zlvx0wB.

Name several properties of materials that could be exploited to mf0 hhc5-e*njpjah sm2h) xc9-ake a thermometercj xhh-f *s) a pe9c-h2mj50hn.

Which is larger, 1 Ca;vbv j5ed22 .dwx;orb u:7g rxyt/+m $^{\circ} $ or 1 F $^{\circ} $?

If system A is in thermal equilibrium with system B, but B is not in theof h3oon9e73+05ez z qp emo-frmal equ7om+h f oeefq9p5z30oen 3o -zilibrium with system C, what can you say about the temperatures of A, B, and C?

A flat bimetallic strip consists of aluminum riveted* hqaf*cu a59q to a strip of iron. When heated, the strip will bend. Which me *qacha u5*fq9tal 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 coeffif lrx bpw-t 9g0ra /7:pf+itl*3gef a8cient 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 c3ejk. (wa0z qgontrol a furnace (or other heating or cooling system). The bimetallic strip consists of two strips of different metals bonded together. 3gk0ej waq.z( 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 the ends often have a section in x w a80np3r-ssthe shape of a 03 r8snwp-a sxU. Why?

A flat, uniform cylinder of lead floats in mercury41 xivn2wtaz7 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 plaxznhdhvh,m ;-3p* 5p1qrr. awced in a hot tub of water, the mercury pzmqha3dw 5;x rnpv*.h,h-1r initially descends a bit and then rises. Explain.

A glass container may break if one part of ivkhgkez u473 0c)p a/lt is heated or cooled more rapidly than adjacent parz 0)/apel7c ukkh43gv ts. Explain.

The principal virtue of Pyrex glass is that its coefficient of linear expa3h,)e i*tjmk,lp5vsmnsion is much smaller thamv5,*ljk hpm 3e)its,n that for ordinary glass (Table 13–1). Explain why this gives rise to the increased heat resistance of Pyrex.

Will a grandfather clock, accu:.f+9tcv waxo;nw-+g2y;m;zi4btc.izs m msrate 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 cp+w.m y2xrlw k;r 24d2y4xzkcause its bottom and top to bulge so badly the can will not stand up. Wh;y 4dzrpy2wxck 2+kmx42wr. l at has happened?

When a gas is rapidly compressed (say, by pushing down a piston), itsek4 n2pj *yb- ut7srm9 temperature increases. Wpse9tb2kmuj yn -47r*hen 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 moving piston.

Will the buoyant force on an aluminum sphere sub kv20 pf/.yn3dy2jf;,y2al lvmmd; oq merged in water increase or decrease if the temperature is increl3/o aym22 ,nlmfp0 f; yqj;2dk yv.vdased from 20 $^{\circ} $ C to 40 $^{\circ} $ C?

Explain in words how Charles’s law follows from kinetic theory and the r sb 0uqbb0,.s4;yubult w38 duelation between average kinetic energyq ysb 408u,t;ubl3ds. bw0buu and the absolute temperature.

Explain in words how Gay-Lussac’s law folg;dxh2ia :w 7nlows from kinetic theory.

As you go higher in the Earth’s atmosphere, the rat mz 1xfosfi8a+im (i o;2dm),sio of $N_2$ molecules to $O_2$ molecules increases. Why?

Escape velocity for the Eqiv 9e(hx- rx8arth refers to the minimum speed an object must have to leave the Earth and never return. The escape velocity for the Moon is about one-fifth what it is for the Ea x8vxe-h9ir q(rth due to the Moon’s smaller mass. Explain why the Moon has practically no atmosphere.

Alcohol evaporates more quickly than water at room temperature. What can you 6e4lv pxi() ipinfer about the molecular properties of on6lx) vpi4e( ipe relative to the other?

Explain why a hot humid day is far more uncomfortable 19g (t;+vf9 toa ugqq6khutl6than a hot dry day at the same temperat;q(lu9a uhtv196 g6ok g+qtfture.

Is it possible to boil water at r *udau4,ae +wroom temperature (20 $^{\circ} $ C) without heating it? Explain.

Consider two days when the air temperature ise qw0dje9 5om02pv3j v the same but the humidity is different. Which is more dep9eewq0 o j0j23d5mvvnse, the dry air or the humid air at the same T? Explain.

Explain why it is dangerous to open the radiator cap of an overheatakic;:jspl 7o wms0-aak.xml1u a;-4ed automobile engine.x wia jl-;4 :cmssauk.1p 7-0kom a;la

Why does exhaled air appear as a little white rok pb157f0lk2rrl h6 cloud in the winter (Fig. 13–28)?

  How many atoms are there inatdbv 7j7 tk (li g4gr(441qnd 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 pgihq1z 7 vi2q. k:+wggpkgi0,1 crr: the number in aizgiq2pi qrgkg + 7vg1pwkr0h. :c:1, silver ring of the same mass?$N_{Au}$ =    $N_{Ag}$

  “Room temperature” is often taken c* yw+a1nbh9b7z gn w(c1lxomggic qe;;+o+0to be 68°F. What is this on the Celsius scale?ngylaq o9mb1cbcen7w+(w gx g1z;0+;i+oh* c   $^{\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 aregjp 0e; )h*q+, r.vx1bh cwh9d.x vakp 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 alcohobt33pde jf.-sr5 ay5 bl column has length 11.82 cm at 0.b3y s.jtbd5 5prf-a3 e0 $^{\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 rijq+m8lo4d2k u.of3 (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 appro3nvv7x (qrhe/g yjq(8ximately 300 m tall. Estimate how much its height changes between July (average temperature of 25°C) and Jan(yhexv (8gv3j/q r q7nuary (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, lisy290g db(tbl j4f p.r8s3arivets that are larger than the rivet 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 diameter is to be placed in a hole 1.869 cm in diamete.jsbg3l s 0airl824( bdtyp9f r at 20 $^{\circ} $ C. To what temperature must the rivet be cooled if it is to fit in the hole?    $^{\circ} $ C

  The density of water at 4 v. 6w6zxe+ lr/gfzq5f$^{\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 cmea. o*ac,ok b)r6av-q in diameter. What will be its change in volume if it ie c- aq6*rkvoa.ba ,o)s heated from 30 $^{\circ} $ C to 200 $^{\circ} $ C?    $ \times10^{ -2}cm^3$

  An ordinary glass is filled to the brim with 350.0 mL ofhge, f8j fs7sai-x 5r9sihz)z )e)x m: 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 bbqd;ydfigrqkou*8 f44cq +: r23/ np$^{\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 mab3lx nh2j+s;u de 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, nac6cg r/d.6 /gpcwi1bhrrow vessel so it can expand in essentially one direction only, show that the effective coefficien6dc b 6/cr/gpgi.hc w1t of linear expansion is approximately equal to the coefficient of volume expansion $\beta$.

(a) Show that the change x21ye-wbuhi 0 in 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 plate of length l and width w has coefficienib39g tgivkt; 7e51 j- zsg5zwu8 um6st of linear exujkgib9zv867e utt gs ;gis5z 1 m5w3-pansion $\alpha$ 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 isotu mjtcne4(8 (zn*ns)yropic solid, $\beta$ = 3$\alpha$ if the amount of expansion is small. $\beta$ and $\alpha$ are the coefficients of volume and linear expansion, respectively. [Hint: Consider a cubical solid, and neglect very small quantities. See also Problem 18 and Fig. 13–30.]

  The pendulum in a grandfather clock is made of brass and keeps perfect time ai yplx45,p8*urr t zemb9+ 4bkt 17 r pkubm,l8b 4x*r e4z5yp+t9i $^{\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 hri 7omhp+ +p8h4x ha5(cieodop173 md as an inside diameter of 0.140 mm. The bulb has a volm+1 4mieoxr77h+o( 5dho apdpipch83ume 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 alumu8+3,bdi,jzb 1yfp lvsj14 asinum cylindrical wheel of radius 0.41 m is rotating about its axle on frictionless bearings with anjb+ azlp8 1visydb,sf, u143jgular 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 lez86c-er 0bsy ra;8i s,ixx0nongth when at 15°C. How much stress is required to keep0-s sibxiz8oc 8ra ne,0yxr6 ; it at this length if the temperature increases to 35 $^{\circ} $ C?    $ \times10^{7 }$ N/$m^2$

(a) A horizontal steel I-beam of 7eqj l,);ct jtcross-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 134au+c3 + ze*dbl.122 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 temperatubmwv -:k:e3yt res 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 tempera2 puiey f3).*y arc1x xi3)jkcture on the Fahrenheit scale?    $^{\circ} $ F

  Typical temperatures in the interior o,/y4ezsj )8tf(2 dnxlnb .x+mw7vr u:czqx (af 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, a o5 8ff8ur6mxeir at atmospheric pressure and a temperature of aboutrum68 e85 foxf 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 wxm e-redi/ 13:w+w xnusing the ideal gas law.    kg/$m^3$

  A storage tank contains 21.6 jjz9d) d3fhfe0nt*w .kg of nitrogen ($N_2$) 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 1vp:swkhon *3bhj9-j contains 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 axhn7 hm2kk6w;ld28x gas is at 10.0$^{\circ} $C and a gauge pressure of 0.350 atm, (a) calculate the volume of the helium gas under these conditions.    $m^3$
(b) Calculate the temperature if the gas is compressed to precisely half the volume at a gauge pressure of 1.00 atm.    $^{\circ} $ C

  What is the pressure inside a 35.0-L container holding 105.0 kg of argon g2ge aa, 7ft,vhas at 38a7 eg, t2afv,h5 K?   $ \times10^{ 8}$Pa

  A tank contains 26.0 kg o:ju7u nt ,s1iwf $O_2$ 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 heatwp6dmjhz:a hna6n;di h).* e/ ing the air inside the balloon, which makes it less dense than the air outside. Suppose the volu; wjp:a*dn)6im/ hzd.6ehha nme 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 aek b-*sofs ui-1 -dzc:ir at 15 $^{\circ} $ C to a gauge pressure of 220 kPa. If the tire reaches a temperature of 38 $^{\circ} $ C, what fraction of the original air must be removed if the original pressure of 220 kPa is to be maintained?    %

  If 61.5 L of oxygen at 18.0uhonn,qu 2xb29on6b7q *qfh9 $^{\circ} $ C and an absolute pressure of 2.45 atm are compressed to 48.8 L and at the same time the temperature is raised to 50.0°C, what will the new pressure be?    atm

  A helium-filled balloon escapes a child’s hand at sea leve4t+mp, uw8m( shv sw5ml 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 molec+eaxm9liib* 3us8vxj,a2( r 4i gpa s/ules / $m^3$ in an ideal gas at STP.    $ \times10^{25 }$ molecules /$m^3$

  How many moles of water are there in 1.000 L? How many moleczzf6xs; 3jb;h ules?    mol    $ \times10^{25 }$ molecules

  Estimate the number o:;jdra+vs ,s xf (a) 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 5og3)7 kl-;h udahsba0 .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 ec2-e yhm0(zc u8evlc * 1ywf3lach 2.0-L breath you inhale that were also in the last breath Galileo2 c(ulcmvye fc *3hey1- 0wlz8 took. [Hint: Assume the atmosphere is about 10 km high and of constant density.]   $\frac{molecules}{breath}$

  (a) What is the average translatm3v4qu.xkk (u ional kinetic energy of an oxygen molecule at STP? uq uk .m(3xk4v   $ \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 spa: vl, feyeu /0dbdmn ,/xl5l 5aq.3cseed of helium atoms near the surface of the Sun at a temperature:/elly5dn,ldx0u c baq3,.s/f5mv ae of about 6000 K.    m/s

  By what factor will the gjp q/mx ,:k0trms speed of gas molecules increase if the temperature is increastgkpx/j: m 0q,ed 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 the following specdk o03br5ov ;eds, given in units of km/s: 6, 2, 4, 6, 0, 4, 1, 8, 5, 3, 7, and 8bo50vc;kd o r3. Calculate the rms speed. $v_{rms}$ =    km/s

  The rms speed of molecules in a gas;l);:tzzbh cxo67*1kl 1n nlvq1 ace a 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+ ilwzoo:5f3s is doubled while its volume is held constant, by what factor do+ w o5:lizs3foes $v_{rms}$ change?   

Show that the rms speed of molecules iu;uu0p agp0 bhue:1.i n a gas is given by $v_{rms}$ = $\sqrt{3P\\rho}$ where P is the pressure in the gas, and $\rho$ is the gas density.

Show that for a mixture of two gases wdq9.m s0gm g7at the same temperature, the ratio of their r.g9q m g07wsmdms speeds is equal to the inverse ratio of the square roots of their molecular masses.

  What is the rms speed of nitrh3 fo3t+fi2 zzogen 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 mohcpee 9y ;p1pxskynl (f8/a6*lecule 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 nia6x8imow rf+; trogen molecules at STP?    $ \times10^{-9 }$m

  (a) Estimate the rms speed of an amino acid whosebmly9pxf*g xe.k( q :: molecular mass is 89 u in a living ce*gqe m yl(xfkpb :.9x:ll 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 be writte20)t;bnrzomu7 3de t kn 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 ub4zowgvpvq69t/m: *tranium, $^{235}$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 pht k5 f6+vu-71,jxjr v.rb quczases can $CO_2$ exist? (b) For what range of pressures and temperatures can $CO_2$ be a liquid? Refer to Fig. 13–21.

Water is in which phase when the pressure is 0.01 atm and the temp vt3/l*im cyt6erature is (a) iy* 6tm /3vtcl90 $^{\circ} $ C, (b) -20 $^{\circ} $ C.

  What is the dew point e9 vywd-q;w d 5;tv:rq(approximately) if the humidity is 50% on a day when the temperatq5 dvwvr9:e dyw;-;q ture is 25 $^{\circ} $ C?$\approx$    $^{\circ} $ C(Round to the nearest integer)

  What is the air pressure at a pla;xyups (j; g8.6bngeace where water boils at 90 $^{\circ} $ C?    torr    Pa    atm

  If the air pressure yu) n7bxpiz9 .96kdzuat a particular place in the mountains is 0.72 atm, estimate the temperature at which watei.76b9uz nkdpxu9 zy)r boils. $\approx$ =    $^{\circ} $ C

  What is the temperature on a day when the partial pressure of whkhtrqh ,9sk;, an5*zhh7 *rk ater is 530 Pa and the relative humidity ihthak,s*z5nh,qk ;*rh 9k7rhs 40%? $\approx$ =    $^{\circ} $ C(Round to the nearest integer)

  What is the partial pressure y:,w/f nlfu.,pn9fln yq i+t4 yowy7*of water 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 wa bp fp1ucqwjx;.,l v8,ter is boiling at a temperature of 18xqwl1;f.p c up jv,,b20 $^{\circ} $ C? Assume no air escaped during the heating process, which started at 20 $^{\circ} $ C.    atm

  If the humidity in a gan-3zj(z p-p3 urvq7 1hvsw0 room 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 point of 5 .w6jy7 w,rew c$^{\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 17 p9qytc )8ggn,eyx 9r3–4) to diffuse a di xr t97,y8 )gyqcpn9egstance 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 -k1md8ing -nc5foi), ijao5oyp- v 5x interior through tiny tubes called tracheae. An average trachea is about 2 mm long 58)fykn 1-5dco-x -a5ignpi,omjiv oand 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 oy6f+ 0ved5oqe q+dwa**9t (7fancm ybeen 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 be10un1j yemxhy7)k faib5mupxq(/0 6 een 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 n:7zn3 fb1du uv qm3d,elx ;.ytemperature. How much error will be made in a recipe calling for 300 mL of cool water, i.u3 1qdnxy n f 3;:l7buezvm,df 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 hel3 *,c5l3sdy ewr0 . fegn-moaxium gas cylinder is initially 28 atm. After many balloons have been blown up, the gauge pressure has decreased to 5 atm. What fraction of the original gas remains in wsg3 x .l,3n*emo0-yce 5 rfdathe cylinder?   

  Estimate the number of air +o)c:f f h-gppmolecules in a room of length 6.5 m, width 3.1 m, and height 2.5 m+)f:fcg oh-pp . 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 abou8lx (e* 3ur wuuxw8z+tt 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 attainab vhua (2 ss0u2d:lozg:le using the best available vacuum techniques is abouguu h :l2s0(da2vozs:t $10^{-12} N/m^2$ At such a pressure, how many molecules are there per $cm^3$ at 0$^{\circ} $C?    $\frac{molecules}{cm^3}$

  If a scuba diver fills his lc cb:;) o*6gl cdglt2f plwi/7ungs to full capacity of 5.5 L when 10 m below the surface, to what volugo7f*i/ c2d:lptlgwcl;c) 6b me would his lungs expand if he quickly rose to the surface? Is this advisable?    L

  A space vehicle returning from the Moon enters Earth’s atmduq( 9 )scjhx(onnl6 1+jo)h dosphere at a speed of about 40,000 km/h Molecules (assume nitrogen) striking the nose of the vehicle with this speed correspond to what temperatuj()non sdd h) +( h6xucq1jo9lre? (Because of this high temperature, the nose of a space vehicle must be made of special materials; indeed, part of it does vaporize, and this is seen as a bright blaze upon reentry.)    K

  The temperature of ano69* n;g,- posfixptk ideal gas is 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 volumebb2hyuz8cg 9v1azd o8c ) ::yh of 770m$^2$ (a) What is the total mass of air inside the house at 20$^{\circ} $C?    kg
(b) If the temperature drops to -10$^{\circ} $C what mass of air enters or leaves the house?    kg

  From the known value of atmospheric p9kuy ))/fr wwjressure at the surface of the Earth, estimate the total number of air molecules in th wy)r9/)w kujfe Earth’s atmosphere.    $ \times10^{44 }$ molecules

  What is the rms speed of nitrogen miz3oz6w gdxv;,g 9y-ik 7 t a)vwoq0z:olecules 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 = 2000 psiaf7bt3o/n4hja 0apx 8 sst 2fez8+km( (13,800 kPa) and at T = 259K How long will the cylinder last if the flow rate, measured at atmospheric pressure, is constant at 2.4 L/min. af ns(mso/+ap 2b3tz8etx 7j0ka hf84$\approx$    hour

  An iron cube floats in a bowl of liquid mercury at 0 q)rpzb ./cumck 7,h+b$^{\circ} $C. (a) If the temperature is raised to 25$^{\circ} $C, will the cube float higher or lower in the mercury? ----待选择----lowerheigher 
(b) By what percent will the fraction of volume submerged change?    %

  The density of gasoline at 0jq6q: )dw)w bnixrbzf 8:b9sz*4tz z v53mc /o$^{\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 equa7+m rf.4v*xp bnwf-sj tor 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 glass jardt*roej9 0 /zzc5ca2o 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 standu 26:g ad6maubard, adopted in the 18$^{th}$ century, was a platinum bar with two very fine marks separated by what was defined to be exactly 1 m. If this standard bar was to be accurate to within $\pm1.0 \mu m$ how carefully would the trustees have needed to control the temperature? The coefficient of linear expansion for platinum is $ 9\times10^{ -6}C/^{-1}$. $\pm$ =    C$^{\circ} $

  A scuba tank, when fully charged, k 279, sw2 k)orl8lgvr0 elgdmhas 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 Eax e :yki 9g6z5idvdr-(rth 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 againsta(4bh9noon 8v l4 ;hbp gravity by tennis balls thrown vertically upward at it. How many tennis balls per second must v;hl4 n(9o bo8 pn4habrebound 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 a 3.00 ep * z-tzich8vcoq 73to66li3e)j9cu-cm-diameter (spherical) bubble of air from a depth of 14.0 m in a lake. Assume the tempe9 cl3izpq*3 zc oitu-j eeo86ct67hv)rature 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 wat1ndxb 4 mt0+izer vapor pressure in the air on the following two days: td1x0in4+zmb
(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 lxec qt:/sl pmx:w . (ag*6ih2iron at STP, and when it is a solid deep in the l*qm6xg:/iac2.lpt ehw x (: sEarth where the temperature is 2000$^{\circ} $C and under 5000 atm of pressure. Assume the bulk modulus (90$\times 10^9N/m^2$) and the coefficient of volume expansion do not vary with temperature and are the same as at STP.    %  ----待选择----decreaseincrease 

(a) Use the ideal gas law to show that, for an ideal gas atzi c (tqhg)7naz0o5-q7mqy2 r constant pressure, the coefficient of volume expansion im0 ) gcozqr27qna5yq thzi(7-s equal to $\beta$ = 1/T where T is the temperature in kelvins. Compare to Table 13–1 for gases at T = 293K (b) Show that the bulk modulus (Section 9–5) for an ideal gas held at constant temperature is B = P where P is the pressure.

  In humid climates, p67pttz73vqu5ask s 5q, os jb)eople constantly dehumidify their cellars to prevent rot and mildew. If the cellar in a h3qa)vusp,q 5 s7skj7ttb o56 zouse (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