Tag: trends in groups and periods

Questions Related to trends in groups and periods

Which of the following properties of hydrogen is incorrect?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Like halogens, hydrogen exists as a diatomic gas

  2. Like halogens, hydrogen exhibits - 1 oxidation state in its compounds with metals

  3. Like halogens, hydrogen is liberated at cathode

  4. The ionization energy of hydrogen is quite close to halogens

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Correct Option: C
Explanation:
Like halogens, hydrogen is liberated at anode, e.g. 
2NaH $\rightarrow 2Na + H _{2} $ (at anode
2NaCl $\rightarrow  2Na + cl _{2}$ (at anode)

The order of reactivity of halogens towards hydrogen is:

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. $F _{2} > Cl _{2} > Br _{2} > I _{2}$

  2. $I _{2} > Br _{2} > Cl _{2} > F _{2}$

  3. $Cl _{2} > Br _{2} > I _{2} > F _{2}$

  4. $Br _{2} > Cl _{2} > F _{2} > I _{2}$

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Correct Option: A

Which of the following statement is correct regarding hydrogen?

chemistry study of the first element - hydrogen position of hydrogen in the periodic table hydrogen in periodic table trends in groups and periods

  1. Hydrogen shows +1 and -1 oxidation states

  2. Hydrogen is never liberated at anode

  3. Hydrogen has same ionisation enthalpy as that of alkali metals

  4. Hydrogen has same electronegativity as of halogens

Show answer
Correct Option: A
Explanation:

Hydrogen has +1 oxidation state in compounds with more electronegative elements e.g. $HF$. It has -1 oxidation state in compounds with more electropositive elements like $NaH$. In the above compounds with $Na$ and $F$ show +1 and -1 oxidation state respectively.