A) iron
B) potassium
C) copper
D) mercury
Correct Answer: A
Solution :
(i) Cu and \[\text{Hg}\]cannot liberate hydrogen from acids because they are placed below hydrogen in electrochemical series. (ii) K liberates H from acids but reacts with \[{{\text{H}}_{\text{2}}}\text{O}\]at room temperature. (iii) Fe is metal which liberates hydrogen from dilute acids and reacts with \[{{\text{H}}_{\text{2}}}\text{O}\]on heating. \[Fe+{{H}_{2}}S{{O}_{4}}(dil.)\xrightarrow{{}}FeS{{O}_{4}}+{{H}_{2}}\] \[Fe+{{H}_{2}}O(steam)\xrightarrow{{}}{{H}_{2}}\uparrow \]You need to login to perform this action.
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