The chemical equation below shows that hydrogen and oxygen chemically react to form water. Which of these is true?

A.

Water is a pure substance and has the same properties as oxygen.

B.

Water is a pure substance and has the same properties as hydrogen.

C.

Hydrogen and oxygen are pure substances that have identical properties to each other.

D.

Hydrogen, oxygen, and water are pure substances that each have different properties.

Acoal-fired plant generates 600 mw of electric power. the plant uses 4.8 x 10^6 kg of coal each day, and the heat of combustion of coal is 3.3x 10^7 j/kg. the steam that drives the turbines is at a temperature of 300° c, and the exhaust water is at 37° c. (a) what is the overall efficiency of the plant for generating electric power? (b) how much thermal energy is exhausted each day? (c) what is the change in entropy of the universe for this heat engine? (d) using the same heat reservoirs, what is the maximum possible (carnot) efficiency for a heat engine?

What is the freezing point of radiator fluid that is 50% antifreeze by mass? kf for water is 1.86 ∘c/m.

The electric potential a distance r from a small charge is proportional to what power of the distance from the charge? a. r^-1 b. r c. r^-2 d. r^2