Chemistry · Ch 4 — Hydrogen
Laboratory Preparation
Laboratory Preparation
The hydrogen used in a school or college laboratory is conveniently generated by letting an active metal -- zinc, iron or tin are the ones typically used -- react with a dilute mineral acid. For zinc with dilute hydrochloric acid:
(Dilute sulphuric acid works just as well in place of hydrochloric acid.) In the apparatus (Figure 4.2), zinc granules sit in a round-bottom flask; dilute acid is added from a tap funnel above, and the hydrogen gas evolved is led away through a delivery tube into a trough of water, where it is collected by downward displacement of water in an inverted gas …
What this figure shows. Apparatus diagram: a round-bottom flask charged with zinc granules (labelled "Zinc") sits on a stand; dilute hydrochloric or sulphuric acid (labelled "Dilute hydrochloric or sulphuric acid") is added into the flask through a tap/thistle funnel at the top. A bent glass delivery tube carries the liberated gas sideways and down into an adjoining water trough, where it bubbles up (labelled "Hydrogen") into an inverted gas jar standing mouth-down in the trough, collecting th …