Hydrogen gas is produced in the lab when dilute hydrochloric acid is reacted with zinc metal.
The word equation for the reaction is:
zinc+hydrochloric acid→zinc chloride+hydrogen \text{zinc} + \text{hydrochloric acid} \rightarrow \text{zinc chloride} + \text{hydrogen} zinc+hydrochloric acid→zinc chloride+hydrogenWrite a balanced chemical equation for this reaction, including state symbols.
A student sets up the apparatus shown below to prepare and collect a sample of hydrogen gas:
State two reasons why this set-up is unsuitable for preparing and collecting hydrogen gas.
If the student replaces the zinc metal with lead metal and uses dilute sulfuric acid, the reaction quickly slows down and stops, even though there is still an excess of lead metal and unreacted acid in the flask. Explain why this happens.
When some hydrogen gas is passed over heated black copper(II) oxide, a reaction occurs and a solid residue is formed. Which of the following substances is this solid residue?
Hydrogen gas consists of simple molecules where the atoms are held together by covalent bonds.
State what is meant by the term covalent bond.
Explain, in terms of structure and bonding, why hydrogen has a low boiling point.
Describe how the outer shell electrons are shared in a molecule of hydrogen, H2\text{H}_2H2.
