Question

In the activity, they're asking us to pass the gas produced in the test tube first into Soap solution, and only after that, asking us to test the presence of Hydrogen. But, what we usually do is, bring a burning splinter near the mouth of the test tube and directly test for Hydrogen know? Then, why is it necessary to pass it through soap solution? What difference does it make?​

Answer 1

because of soap solution it makes bubbles which are helpful to us to see the hydrogen and easier to burn the hydrogen

Answer 2

No major difference, as hydrogen gas doesn't burn profusely with a flame, it can be difficult to identify the presence of a gas just by using a burning splinter. Also the amount of gas produced is quite less, it's used to ensure that he gas produced is hydrogen(pop sound) and not any other gas.

On passing hydrogen gas through soap solution it does not get dissolved in it, and the solution easily forms bubbles containing hydrogen gas. Also hydrogen gas bubbles are not formed with just water. Therefore, soap solution can be used in testing of hydrogen gas.

Further using a burning splinter in a lab is fun! This activity is meant to be performed in your school's chemistry lab!

Hope it helps.

God Speed.