Tag: p- block elements-ii

Questions Related to p- block elements-ii

State True or False.
Before 1961, the atomic weight standard for elements was based on oxygen and not carbon.

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. True

  2. False

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Correct Option: A
Explanation:

True.

Before 1961, oxygen was used as the reference standard, with an assigned value of 16. The unit of atomic mass was thereby defined as $ 1/16$ the mass of an oxygen atom.

The most abundant non-metal in the earth's crust is:

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. chlorine

  2. hydrogen

  3. silicon

  4. oxygen

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Correct Option: D
Explanation:

Aluminium is the first most abundant metal while iron is the second most abundant metal on earth. It is the fourth most common element in the earth's crust. Oxygen is the most abundant non metal and second is silicon present on earth's crust.

The element name 'oxygen' comes from Greek words which means: 

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Fire-starter

  2. Rust

  3. Air

  4. Acid-producing

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Correct Option: D
Explanation:

The element name "oxygen" came from the greek words $oxys$ and $genes$, which together mean $"acid \ forming"$.

Statement 1: By mass, oxygen is the most abundant element in the human body.
Statement 2: It is principally found as $O _2$ in the bloodstream.

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Both Statement 1 and Statement 2 are correct and Statement 2 is the correct explanation of Statement 1.

  2. Both Statement 1 and Statement 2 are correct, but Statement 2 is NOT the correct explanation of Statement 1.

  3. Statement 1 is correct, but Statement 2 is not correct.

  4. Statement 1 is not correct, but Statement 2 is correct.

Show answer
Correct Option: C
Explanation:

By mass, oxygen is the most abundant element in the human body.

Oxygen is found in the human body as oxy-haemoglobin in the bloodstream but not as $O _2$

So statement 1 is correct but not 2.
Hence option C is correct.

Which of the following has highest ionic radius :

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. $F^-$

  2. $B^{3+}$

  3. $O^{2-}$

  4. $Li^+$

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Correct Option: C
Explanation:

Anions are of larger radius than neutral atom and smallest is cation
$O^{3-}  >  F^-  >  Li^+  >  Bi^{3+}$

Which of the following is illustration of pyrosilicate?

chemistry p- block elements-ii group 16 elements - general properties group 16 elements - trends in chemical properties group 16 elements

  1. Zircon

  2. Hemimorphite

  3. Beryl

  4. Asbestos

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Correct Option: A
Explanation:
Zircon is a pyrosilicate named as Zirconium silicate whose chemical formula is  $ZrSiO _4$.Which is used  as gem stone.
Hence option  A is correct.

Which of the following is used to prepare $Cl _{2}$ gas at room temperature from concentrated $HCl$?

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

  1. $MnO _{2}$

  2. $H _{2}S$

  3. $KMnO _{4}$

  4. $Cr _{2}O _{3}$

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Correct Option: A,C
Explanation:

Manganese dioxide($MnO _2$) is heated with concentrated $HCl$ to form $Cl _2$

$MnO _2+4HCl\rightarrow MnCl _2+Cl _2+2H _2O$

 $HCl$ in action with potassium permanganate gives $C _2$

$2KMnO _4+16HCl\rightarrow 2KCl+2MnCl _2+8H _2O+5Cl _2$.

Hence option A and C is correct.

Which of the following statements is not correct?

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

  1. All the oxides of halogens are powerful oxidants.

  2. The compounds of oxygen and fluorine are not called oxides but fluorides.

  3. Oxygen fluorides form oxoacids.

  4. In oxyhalides, bonds are mainly covalent due to small difference in electronegativity of oxygen and halogens.

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Correct Option: C
Explanation:

Oxygen florides forms $HF,O _2$ on hydrolysis.

$OF _2 + H _2O\rightarrow O _2 + 2 HF$

$2O _2F _2 + 2H2O\rightarrow O _2 + 4HF$

so oxygen florides do not form forms hypohalous acids.

So the given statement oxygen florides forms oxoacids is wrong.

Hence option C is correct.

Bleaching powder and bleach solution are produced on a large scale and is used in several house-hold products. The effectiveness of bleach solution is often measured by iodometry. Bleaching powder contains a salt of an oxoacid as one of its components. The anhydride of that oxoacid is:

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

  1. $Cl _{2}O$

  2. $Cl _{2}O _{7}$

  3. $ClO _{2}$

  4. $Cl _{2}O _{6}$

  5. $Cl _2O _3$

  6. $Cl _2O _5$

  7. $Cl _3O _9$

  8. $Cl _3O _5$

Show answer
Correct Option: A
Explanation:

Bleaching powder is $Ca(OCl)Cl$.


So, bleaching powder contains a salt of $HOCl$.

$Cl _2O$ is an anhydride of $HOCl$.

$Cl _2O+H _2O\Rightarrow 2HOCl$.

Hence, option A is correct.

Hypo chlorite radical is represented as $(HClO _2)^{-1}$.

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

  1. True

  2. False

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Correct Option: B
Explanation:

Hypochlorite radical is represented as $ClO^-$. Thus the given statement is false.