C. Lowering the temperature
At the lower temperature, particles have less kinetic energy, so they move slower.
Answer : The molecular weight of a gas is, 128.9 g/mole
Explanation : Given,
Density of a gas = 5.75 g/L
First we have to calculate the moles of gas.
At STP,
As, 22.4 liter volume of gas present in 1 mole of gas
So, 1 liter volume of gas present in
mole of gas
Now we have to calculate the molecular weight of a gas.
Formula used :

Now put all the given values in this formula, we get the molecular weight of a gas.


Therefore, the molecular weight of a gas is, 128.9 g/mole
He used a tube of mercury and marked the height of the mercury when placed in an ice bath as 0 degrees celsius, when he placed the tube in a boiling, he marked the height of mercury and called that 100 degrees celsius, he marked it linearly between 0-100 degrees celsius