At what temperature is a gas likely to have the lowest rate of diffusion? 15° 21° 24° 30°

AT 15°

The rate of diffusion of a gas is directly proportional to the absolute temperature. At lower temperature the gas particles have less kinetic energy than at higher temperature. This makes the particles travel faster at higher temperature than lower temperature.

At 15° the gas will have lowest rate of diffusion.

Explanation:

Temperature directly affects the kinetic energy of gas molecules. The energy of motion is called kinetic energy. So if we increase the temperature of gas the average kinetic energy of the gas molecules will increase (they will move faster). Due to increase in kinetic energy they will easily diffuse from their higher concentration to lower concentration (which is diffusion).

Hence the rate of diffusion at given temperature will have following increasing order.

15° < 21° < 24° < 30°

we can conclude that the melting point of table salt is above room temperature (it's actually 801 deg c). the melting point of mercury must be below room temperature (- 39 deg c).

the density of gold = 19.3 g/cm3

the relation between density and mass and volume is

density = mass / volume

given :

mass of gold = 13 g

density = 13g / volume = 19.3

volume = 13 /19.3 = 0.67 cm^3

thus volume of gold nugget = 0.67 cm^3