Which of the following statements are true?
1) All the gas molecules in a sample cannot have the same kinetic energy.
2) The temperature of a gas sample is independent of the average kinetic energy.
3) There are gas molecules that move faster than the average.
4) The average kinetic energy of gas molecules increases with increasing temperature.
5)The average speed of gas molecules decreases with decreasing temperature.
http://chemed.chem.purdue.edu/genchem/topicreview/bp/ch4/kinetic4.html
To determine which statements are true, let's analyze each one:
1) All the gas molecules in a sample cannot have the same kinetic energy.
This statement is true. According to the Maxwell-Boltzmann distribution, which describes the energy distribution of gas molecules, the kinetic energy of gas molecules follows a range of values. Since molecules in a gas sample have different masses and velocities, their kinetic energies will also vary.
2) The temperature of a gas sample is independent of the average kinetic energy.
This statement is not true. In fact, the temperature of a gas sample is directly proportional to the average kinetic energy of its molecules. Temperature is a measure of the average translational kinetic energy of the gas particles. As the kinetic energy increases, so does the temperature, and vice versa.
3) There are gas molecules that move faster than the average.
This statement is true. In any gas sample, there will be molecules that have velocities higher than the average velocity. The distribution of molecular speeds follows the Maxwell-Boltzmann distribution, which means there is a range of velocities and some molecules will have higher speeds than the average.
4) The average kinetic energy of gas molecules increases with increasing temperature.
This statement is true. As mentioned earlier, temperature is directly proportional to the average kinetic energy of gas molecules. When the temperature increases, the average kinetic energy of the gas particles increases as well.
5) The average speed of gas molecules decreases with decreasing temperature.
This statement is also true. According to the Maxwell-Boltzmann distribution, the average speed of gas molecules is directly proportional to the square root of the temperature. As the temperature decreases, the average speed of the gas molecules will also decrease.
In summary, the true statements are:
1) All the gas molecules in a sample cannot have the same kinetic energy.
3) There are gas molecules that move faster than the average.
4) The average kinetic energy of gas molecules increases with increasing temperature.
5) The average speed of gas molecules decreases with decreasing temperature.