Question

What do you observe when hydrogen gas is passed through a soap solution?

Answer 1

Hint: Hydrogen gas being a non -polar molecule is insoluble in the water and being not soluble it comes to the water surface. When we bring flame near the water,it gives a pop sound. Now, answer it.

Complete answer:
Soaps are sodium or potassium salts of long chain of fatty acids(which consists of long chain of hydrocarbon and a terminal carboxyl group) and its chemical formula is $C_{17}{H}_{35}CO{O}^{-}$ along with either $N{a}^{+}$ or $K^{+}$ . It is mainly used for cleaning purposes and lubrication (means making the surface smooth). Although, it is a very good cleansing agent but it’s not very effective when it is used in the hard water which contains mineral salts in it and is responsible for its hardness.
Soap solution is prepared by dissolving the soap into the water resulting into its solution. When hydrogen gas is made to pass through the soap solution ,then we observes that the hydrogen gas doesn’t get dissolved into the soap solution because hydrogen molecule being non-polar (i.e. when electrons are shared equally between the two atoms and they have neither positive nor negative charge) and doesn’t forms the hydrogen bonds with the water molecules and so insoluble in water. Since, it’s not soluble in the soap solution the hydrogen gas tries to escape out of soap solution and thus, when the hydrogen gas reaches the surface of water it results in the formation of bubbles and the bubbles are present in lesser so the hydrogen gas tries to escape into the environment which provides it with more space.
So, since the hydrogen gas is not dissolved in water and results in the formation of bubbles, so therefore, the soap solution can be used in the testing of the hydrogen gas.

Note: Don’t get confused in the polar and nonpolar molecules. They are both different in meaning, polar molecules are those which after gaining or losing the electrons acquire either negative or positive charge respectively. On the other hand, in non-polar molecules electrons are shared equally and hence, there are no positive or negative charges.