SQA National 5 Chemistry Practice Exam

Heating metal oxides with carbon is a method commonly used in metallurgy, specifically in the extraction of less reactive metals. When metal oxides are heated with carbon, a reduction reaction occurs, where carbon acts as a reducing agent, converting the metal oxide back into the metal and producing carbon dioxide as a byproduct.

Zinc and lead are prominent examples of metals that can be extracted from their respective oxides through this method. When zinc oxide is heated with carbon, zinc is produced, while lead oxide can similarly be reduced to yield lead. This is an established technique in the metallurgical extraction process for these metals, especially since they are situated below carbon in the reactivity series.

The other choices include metals like gold and platinum, which are not typically obtained through reduction with carbon due to their noble characteristics and lack of reactivity. Iron and copper can be extracted from some ores using carbon, but zinc and lead are more directly associated with reduction reactions using carbon as the reducing agent. Mercury and silver similarly do not rely on this method of extraction when considering the most common and efficient processes for obtaining them from their ores. Hence, the option featuring zinc and lead accurately reflects metals that can be effectively obtained through heating their oxides with carbon.