Tag: p-block elements

Quizzes (27) Questions (202)

Questions Related to p-block elements

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

The oxidation state of Chlorine in Bleaching Powder:

  1. -2
    • 1
    • 1

  4. -1 and + 1
Reveal answer Fill a bubble to check yourself
D Correct answer
Explanation

The chemical formula of bleaching powder is $CaOCl _{2}$. Here, calcium is bonded to $Cl^{-}$ ion and $OCl^{-}$ ion respectively.

In $Cl^{-}$ the oxidation state of chlorine is -1 and in $OCl^{-}$ ion the oxidation state of chlorine is +1.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Which has maximum pH in aqueous solution ? 

  1. $NaClO$
  2. $NaClO _2$
  3. $NaClO _3$
  4. $NaClO _4$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

$NaClO$ has the maximum $pH$ because the acidic strength decreases with decreasing $O$ atoms in oxy acids . Since $NaClO$ has the lowest oxygen atom among given options, it will have least acidic strength and hence, a maximum $pH$.

Multiple choice oxoacids of halogens p- block elements-ii p-block elements the p-block elements chemistry

Which one of the following anions can undergo both oxidation and reduction?

  1. $Cr _2{O _7}^{2-}$
  2. $N{O _3}^{-}$
  3. $OCl^-$
  4. ${S}^{2-}$
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

$(A)$ In $Cr _2{O _7}^{2-}$, the oxidation state of $Cr$ is $+6$, which is maximum oxidation of $Cr$. It can only lower down its oxidation state. So, it acts only as an oxidising agent.
$(B)$ In $N{O _3}^{-}$, the oxidation state of $N$ is $+5$, which is the maximum oxidation of $N$. It can only lower its oxidation state  and so, it acts only as an oxidising agent.
$(C)$ In $OCl^-$, the oxidation state of $Cl$ is $+1$ and $Cl$ shows oxidation state from $-1$ to $+7$ and so, it can undergo both oxidation and reduction.
$(D)$ In ${S}^{2-}$, the oxidation state of $S$ is $-2$, which is the minimum oxidation state of $S$ and so, it can only increase its oxidation state and hence, it acts only as a reducing agent.

Therefore, $OCl^-$ can undergo both oxidation as well as reduction.