Answer: <span>Fuel cells do not need an extra or rechargeable battery to operate the electronics.
Explanation:
The fuel cells are the batteries pe se. The cars do not need an extra battery and the batteries are not rechargeable.
The cells produce the electric power from the combination of hydrogen and oxygen.
</span>Regarding the other choices, fuel cells use hydrogen gas which needs high pressure, resulting in requiring <span>heavy steel tanks and isolation.
Of course the hydrogen gas is not as wideley distributed
throughout the country as conventional fuel.
And the tecnology is yet expensive.</span>
Answer:
Option D
A reversible process is one in which a large change in conditions can reverse its direction.
Explanation:
A. Temperatures of a few nanokelvins can be achieved in a Bose-Einstein condensate. TRUE
b. A perfect crystal of any substance at 0 K has minimum entropy. is TRUE
c. The standard molar entropy of a substance at temperature T is a measure of the quantity of energy that must be dispersed in that substance for it to exist at T. is TRUE
d. A reversible process is one in which a large change in conditions can reverse its direction. is FALSE
e. Entropy is a measurement of the nanoscale dispersal of energy in a sample of matter. is TRUE
A reversible reaction is one that can return to it's normal direct even if an infinitesimal change is applied to some of it's conditions.
Answer:
True
Explanation:
It's true because the pH is a measure of how basic or acid a solution is. In an acidic medium, the pH scales goes from 0 to 7. While in a basic medium goes from 7 to 14. The lower the pH value of the most acid the solution is.
1. The expression pH = -log(molar concentration of hydronium) allow to calculate the pH of a solution.
2. On the other hand, the expression pOH = -log(molar concentration of hydroxide) allow to determine the pOH of a solution.
The values of pH and pOH always obey the following expression:
pH + pOH = 14
Thus if for instance the pH becomes smaller the pOH must become bigger in order to fulfill the equation. Which means that the concentration of hydronium ions is greater than the hydroxide concentration.
For example, in an acidic medium:
if pH= 3, pOH= 11
In this case the molar concentration of hydronium is 0,001M. And the molar concentration of hydroxide ions is just 0,00000000001M.