Answer:
a. Work, ΔE is negative;
b. Work, ΔE is negative;
c. Work, ΔE is positive.
Explanation:
In the three cases, there is energy exchange in primarily work. The heat is the energy flow because of the difference in temperature. Of course, some heat may be lost in the cases by dissipation.
In the letter <em>a</em> the system is at an initial velocity different from 0, and then it stops. The energy that is represented here is the kinetic energy, which is the energy of the movement. Note that the system goes from a higher velocity to 0, so it is losing kinetic energy, or work, so ΔE = Efinal - Einitial < 0.
In letter <em>b</em>, the system is falling from a certain high to the floor, so its gravitational potential energy is change. That potential energy represents the energy that gravity does when an object shifts vertically. Because it goes from a high to 0, the energy is been lost, so ΔE = Efinal - Einitial < 0.
In letter <em>c</em>, the system is going higher and with higher velocity, so there is a greatness in the gravitational potential energy and the kinetic energy, both works, so ΔE = Efinal - Einitial > 0.
Explanation:
This is due to a reduction in atmospheric pressure – pressure due to the weight of the overlying air column). Remember that the higher the altitude the lower the air density and subsequently the lower the air pressure.
Therefore when heating water at higher altitude the vapor pressure of the water at the surface overpowers the atmospheric pressure – which is slightly lower than at sea level – even before the water temperatures reach 100 degrees centigrade.
AgNO3 + Cu = Cu(NO3)2 + 2Ag .. this is an example of a single replacement reaction.
Answer the glucose is then turned back into carbon dioxide, which is used in photosynthesis
Explanation: :)
Entropy change of vaporization is simply the ratio of
enthalpy change and the temperature in Kelvin.
Temperature = 64 + 273.15 = 337.15 K
Hence,
δsvap = (32.21 kJ / mole) / 337.15 K
<span>δsvap = 0.0955 kJ / mole K = 95.5 J / mole K</span>
