Tag: chemistry

Questions Related to chemistry

Which of the following is/are peroxide(s) ?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $ PbO _{2} $

  2. $ H _{2}O _{2} $

  3. $ SrO _{2} $

  4. $ BaO _{2} $

Show answer
Correct Option: B,C,D
Explanation:

In $ {PbO} _{2}, $ Its $ Pb^{+4}$ & $ 2O^{-2} $


In $ {H _{2}O} _{2},$ there is peroxide linkage

$ H-O-O-H $ 

In $ SrO _{2}, $ as Sr is alkaline earth metal 
$ \therefore $ Its $ Sr^{2+} $

$ \therefore $ Its $ O _{2}^{-2}, (\bar{O}-\bar{O}) $ peroxide linkage 

In $ BaO _{2},$ Its $ Ba^{{+2}}\therefore O _{2}^{-2} $

$ \bar{O}-\bar{O} $ peroxide linkage 

Hence, the correct options are $\text{B}$, $\text{C}$ and $\text{D}$

Which of the following oxides is amphoteric in character?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $CaO$

  2. $CO _2$

  3. $SiO _2$

  4. $SnO _2$

Show answer
Correct Option: D
Explanation:
Option (D) is correct.
$SnO _2$ is amphoteric in character.
$SnO _2 + 2NaOH \rightarrow Na _2SnO _3 + H _2O$
$SnO _2 + 4HCl \rightarrow SnCl _4 + 2H _2O$+$CO _2$ is acidic in character.
$SiO _2$ is very weak acid.
$CaO _2$ is basic in nature.

A metal oxide is acidic when :

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $\sqrt{\varphi}\, <\, 2.1$

  2. $\sqrt{\varphi}\, =\, 2.1\, to\, 3.2$

  3. $\sqrt{\varphi}\, >\, 3.2$

  4. None of these

Show answer
Correct Option: C
Explanation:

A metal oxide is acidic when $\sqrt{\varphi}\, >\, 3.2$

Which of the following oxides is/are not amphoteric in character?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. CaO

  2. $CO _2$

  3. $SiO _2$

  4. $SnO _2$

Show answer
Correct Option: A,B,C
Explanation:

$CaO$, $CO _2$ and $SiO _2$ when dissolved in water gives base ,hence they are basic oxides.


$SnO _2$ do not react with water, so it is amphoteric. 

Hence options A,B, & C are correct.

Which of the following oxides are not neutral?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $CO$

  2. $SnO _2$

  3. $ZnO$

  4. $SiO _2$

Show answer
Correct Option: B,C,D
Explanation:

 $CO$ is a neutral oxide insoluble in water, but behaves as amphoteric compound. 


$SiO _2$ amphoteric oxide, $SnO _2$ basic oxide and  $ZnO$  is amphoteric oxide.

Hence options B,C & D are correct.

Select the correct statements:

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. s-block metal oxides are basic in nature, except $BeO$ which is amphoteric.

  2. p-block metal oxides are acidic in nature, except $NO$,$ N _2O$,$ CO$.

  3. d-block metal oxides are basic, acidic, and amphoteric in nature.

  4. d-block metal oxides are only basic in nature.

Show answer
Correct Option: A,B,C
Explanation:

(A) BeO is amphoteric in nature. It reacts with acids as well as alkalies.  Oxides of other s block metal elements are basic in nature. They react only with acids. hence, the option A is correct.

(B) The oxides $NO, N _2O,CO$   are neutral. Whereas the  remaining oxides of p block metals are acidic in nature. Thus, the option B is correct.

Some of the d block metal oxides are basic in nature, some of them acidic in nature where as the rest are amphoteric in nature. Thus, the option C is correct and option D is incorrect.

The species that do not contain peroxide ions is :

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $PbO _2$

  2. $H _2O _2$

  3. $SrO _2$

  4. $BaO _2$

Show answer
Correct Option: A
Explanation:

Only true peroxides which have -O-O- bond give hydrogen peroxide with dilute acids.
$PbO _2$ does not give hydrogen peroxide with dilute acids. So it is not a true peroxide.

Hence option A is correct.

Which one of the following statement is true?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. According to the modern atomic theory, atoms of the same element may have different atomic weights

  2. Reduction is the process of electron loss

  3. Acidic oxide are the non-metallic oxides

  4. The solubility of all substances decreases with increase in temperature

Show answer
Correct Option: C
Explanation:

Acidic oxides are the oxides which reacts with water to form an acid. Acidic are non- metallic oxides. Some of the examples are ${ SO } _{ 3 }$ forms sulphuric acid and ${ CO } _{ 2 }$ forms carbonic acid. 

So, correct answer is option C.

Which choice or choices demonstrate amphoterism?
i. $HCl + H _{2}O \rightarrow H _{3}O^{+} + Cl^{-}$ and $H _{2}O + N _{3} \rightarrow OH^{-} + NH _{4}^{-}$
ii. $HS^{-} + HCl \rightarrow Cl^{-} + H _{2}S$ and $HS^{-} + NH _{3} \rightarrow NH _{4}^{+} + S^{2-}$
iii. $HCl + NaOH \rightarrow NaCl + H _{2}O$ and $NaCl + H _{2}O \rightarrow HCl + NaOH$

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. i only

  2. ii only

  3. iii only

  4. i and ii only

  5. i and iii only

Show answer
Correct Option: D
Explanation:

Amphoteric compound or ion is a molecule that cn act as both acid as well as base.

In the first reaction, $H _2O$ acts as both acid and base.It accepts proton and loses proton. Hence. it shows amphoterism.
In the second reaction, ${ HS }^{ - }$ does the same thing.
It accepts and loses proton. 
Hence, both shows amphoterism.

Which one among the following can be classified as amphoteric?

chemistry chemistry of non-metals oxides of elements simple oxides oxygen

  1. $Na _3PO _4$

  2. HCl

  3. NaOH

  4. $HSO^- _4$

  5. $C _2O^{2-} _4$

Show answer
Correct Option: D
Explanation:

$\displaystyle HSO^- _4$ can be classified as amphoteric. It can donate a proton and act as an acid. At the same time, it can accept a proton and act as a base.
$\displaystyle HSO^- _4 \rightarrow H^+ + SO _4^{2-}$
$\displaystyle HSO^- _4 + H^+ \rightarrow H _2SO _4$