Answer:
24a. WX, XW
24b. XY
24c. WV
24d. UV, VU
24e. XY, YX
24f. YX
24g. VW
24h. YZ, ZY
24i. VW, WV
24j. WX
25a. ≈ 20°C
25b. ≈ 290°C
25c. ≈ 20°C
25d. ≈ 290°C
Explanation:
Let's look at the graph and see what phase changes happen as we go from U to Z.
UV: the substance is a solid. As heat is added, temperature increases.
VW: the solid begins to melt. The temperature stays constant as the combination of solid and liquid becomes more and more liquid.
WX: the solid is done melting, and there's only liquid now. As heat is added, temperature increases.
XY: the liquid begins to boil. The temperature stays constant as the combination of liquid and gas becomes more and more gas.
YZ: the liquid is done boiling, and there's only gas now. As heat is added, temperature increases.
If we reverse the direction, YX represents condensation instead of boiling, and WV represents freezing instead of melting.
Kinetic energy of molecules increases with temperature. The greatest increase in temperature is also the greatest increase in kinetic energy.
