Chapter 18: A Macroscopic Description of Matter

A concrete bridge is built of 325-cm-long concrete slabs with an expansion joint between them. The slabs just touch on a ${115}^{0}F$day, the hottest day for which the bridge is designed. What is the gap between the slabs when the temperature is $0^{0}F$?

A surveyor has a steel measuring tape that is calibrated to be 100.000 m long (i.e., accurate to$\pm 1mm$) at $20°C$. If she measures the distance between two stakes to be 65.175 m on a $3°C$day, does she need to add or subtract a correction factor to get the true distance? How large, in mm, is the correction factor?

Two students each build a piece of scientific equipment that uses a 655 mm-long metal rod. One student uses a brass rod, the other an invar rod. If the temperature increases by $5.0°$C, how much more does the brass rod expand than the invar rod?

A 60.00 L fuel tank is filled with gasoline on a –$10°C$day, then rolled into a storage shed where the temperature is $20°C$. If the tank is not vented, what minimum volume needs to be left empty at filling time so that the tank doesn’t rupture as it warms?

What is the temperature in $°$F and the pressure in Pa at the triple point of (a) water and (b) carbon dioxide?

A cylinder contains nitrogen gas.A piston compresses the gas

to half its initial volume.

a. Has the mass density of the gas changed? If so, by what factor?

If not, why not?

b. Has the number of moles of gas changed? If so, by what factor?

If not, why not?

A cylinder contains nitrogen gas. A piston compresses the gas

to half its initial volume. Afterward,

a. Has the mass density of the gas changed? If so, by what factor?

If not, why not?

b. Has the number of moles of gas changed? If so, by what factor?

If not, why not?

The nucleus of a uranium atom has a diameter of 1.5 * 10-14 m

and a mass of 4.0 * 10-25 kg. What is the density of the nucleus?

The sample in an experiment is initially at 10C. If the sample’s

temperature is doubled, what is the new temperature in C?

3.0 mol of gas at a temperature of -120$°$C fills a 2.0 L

container. What is the gas pressure?