# How do I test for the presence of hydrogen gas?

##### 1 Answer
May 13, 2016

${H}_{2} \left(g\right) + \frac{1}{2} {O}_{2} \left(g\right) \rightarrow {H}_{2} O \left(g\right)$

#### Explanation:

The classic test is to put your thumb over the end of the test-tube, and then put a lit splint (a match) near the end. The hydrogen will ignite with a loud pop. These days we are almost out of the flame age in a laboratory, but this is certainly a valid and repeatable test.