Question 1
Of Ca, Mg, Cu, Zn, Al and Fe, which metal does not react with dilute hydrochloric (HCl) acid?
The right answer is the one marked above.
Copper (Cu). In activity 16.6 no gas bubbles came from the tube containing copper.
Magnesium, aluminium and zinc bubble rapidly and iron slowly. Copper is less reactive than hydrogen, so it cannot displace the hydrogen in the acid.