Question

Which sample has particles with the lowest average kinetic energy?

(1) 1.0 g of I2 at 50.°C
(2) 2.0 g of I2 at 30.°C
(3) 7.0 g of I2 at 40.°C
(4) 9.0 g of I2 at 20.°C

Answer 1

Answer : Option 4) 9.0 g of
`I_(2)` at 20°C

Explanation : Usually the average kinetic energy depends upon the state of the matter. Considering about the iodine at lower temperature the kinetic energy is found to be low. Whereas at higher temperature has higher kinetic energy value.

From the kinetic energy equation it can be easily related that K.E. is directly proportional to the temperature.

Refer the attached image for the relationship of temperature with kinetic energy.

Answer 2

The question asks average kinetic energy. So it is only related with the temperature. The higher temperature is, the higher kinetic energy is. So the answer is (4).