Question

5. Beakers P and Q both contain the same amount of water, but at 30°C and

70°C respectively. If we could see the molecules of water in P and Q we
would find that
a. There is no difference in the nature of the molecules or the speed at which
they are moving in the two beakers.
b. There is no difference in the nature of the molecules but the molecules in
Q are moving faster than those in P.
c. Molecules in Q are moving faster than in P and some of them have split
into hydrogen and oxygen atoms.
d. The speed of molecules in P and Q are similar, but some in Q have split
into hydrogen and oxygen atoms

Answer 1

The correct answer is that there is no difference in the nature of the molecules in beakers P and Q, but the molecules in Q, which is at a higher temperature, are moving faster than those in P.

Step-by-step explanation:

The question relates to the kinetic molecular theory and the behavior of water molecules at different temperatures. If beakers P and Q contain water at 30°C and 70°C respectively, there will be no difference in the nature of the molecules in the two beakers. The difference is in the speed of the molecules, with those in beaker Q (at the higher temperature) moving faster than those in beaker P (at the lower temperature), as higher temperature is associated with higher kinetic energy. Molecules do not split into hydrogen and oxygen atoms at these temperatures; that would require electrolysis or thermal decomposition at far higher temperatures. Therefore, the correct answer to the question is (b): 'There is no difference in the nature of the molecules but the molecules in Q are moving faster than those in P.'