Question

why the hydrogen gas passes through the soap water

Answer 1

On passing hydrogen gas through soap solution it does not get dissolved in it, and the solution easily form bubbles containing hydrogen gas. The presence of hydrogen gas can be tested with the help of a burning splinter near the bubbles. Then a popping sound will come. Since hydrogen gas bubbles are not formed with water. Therefore, soap solution can be used in testing of hydrogen gas.

Answer 2

as it produces bubble sounds on passing through soapy water nd by carrying a burning candle near it.