Question

four metals A,B,C and D are tested with water steam and dilute hydrochloric acid and its observation is listed below
Between which two metals should hydrogen be placed in the series ?
a) A and B
b) B and D
c) A and C
d) C and D ​

Answer 1

Answer:

Metals which are high above in the activity series react with normal water te replace H2, whereas those below it displace H2 from hot water/Steam. Metals below them can replace H2 from acids. But the Metals below H2 in the series cannot displace H2 on reaction with any of these three.

Answer 2

When four metals A, B, C, and D are tested with water steam and dilute hydrochloric acid it is observed that hydrogen can be placed between B and D metal. (OPTION B)

Explanation

REACTIVITY SERIES -  

• An activity series of metals in which metals are arranged in decreasing order of their reactivity.
• The metals high in reactivity are placed at the top and show chemical reactions with steam, water, or dilute hydrochloric acid.
• The least reactive metals are placed at the bottom of the series and are highly unreactive.
• The moderately reactive metals that are placed below highly reactive metals and above hydrogen do not react with water or steam.
• In the test, metal B does not react with water and steam but reacts with acid therefore, is moderately reactive.
• Metal D is highly unreactive and does not show reaction with water, steam, and acid.
• The hydrogen is placed between moderately reactive (B) and unreactive metals (D).
• The reactivity series of the metals in decreasing order is -

                                  C > A > B > D