MW of gas : 124.12 g/mol
<h3>Further explanation </h3>
Density is a quantity derived from the mass and volume
Density is the ratio of mass per unit volume
With the same mass, the volume of objects that have a high density will be smaller than objects with a smaller type of density
The unit of density can be expressed in g/cm³ or kg/m³
Density formula:

ρ = density
m = mass
v = volume
glass vessel wieight = 50 g
glass vessel + liquid = 148 ⇒ liquid = 148 - 50 =98 g
volume of glass vessel :

An ideal gas :
m = 50.5 - 50 = 0.5 g
P = 760 mmHg = 1 atm
T = 300 K

Solids have a definite shape, and a definite volume.
Liquids have a definite volume, but have no definite shape.
Gas have neither a definite volume nor a definite shape.
Hope this helps!
You can detect salt in water without tasting by measuring the density of the water. Place a glass of spring water and a glass of the suspected salt water on a balance scale and the heavier one contains salt. Other ways to test for salt in water is to put a drop of water on the end of a nail and place in a gas flame. If the water contains salt, the flame will turn a yellow/orange color.