Tag: oxides of elements

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Questions Related to oxides of elements

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

Which of the following are basic oxides? 
$Mn _2O _7$ ,$V _2O _3$, $V _2O _5$, $Cr _2O _3, CrO$ 

  1. $Mn _2O _7$ and $V _2O _3$
  2. $V _2O _3$ and $CrO$
  3. $CrO$ and $Cr _2O _3$
  4. $V _2O _5$ and $V _2O _3$
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

As metallic character decreases as we move across the period then basicity of oxides increases.

Also, we know oxide in lowest oxidation state of element is more basic. So, in $V _2O _3$ and $CrO$, oxidation state of $V$ and $Cr$ are $+3$ and $+2$ respectively which is lowest among others.

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

Select the correct option regarding the properties of dioxygen?

  1. Dioxygen never reacts with metals.

  2. Dioxygen is diamagnetic in nature.

  3. Combination of dioxygen with other elements is highly exothermic process.

  4. Dioxygen liquefies at 55 K and freezes at 90 K.
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

Dioxygen reacts with metals and is paramagnetic. It combines with other elements to form oxides where the reaction is highly exothermic.

Multiple choice chemistry p-block elements oxides of elements simple oxides oxygen

A group of acidic oxide is:

  1. $CrO _{3},Mn _{2}O _{7}$
  2. $ZnO,Al _{2}O _{3}$
  3. $CaO,ZnO$
  4. $Na _{2}O,Al _{2}O _{3}$
Reveal answer Fill a bubble to check yourself
A Correct answer
Explanation

here,${ CrO } _{ 3 }$ are acidic oxides

${ CrO } _{ 3 }+{ H } _{ 2 }O\longrightarrow { H } _{ 2 }{ CrO } _{ 4 }\ { Mn } _{ 2 }{ O } _{ 7 }+{ H } _{ 2 }O\longrightarrow { 2HMnO } _{ 4 }$

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

$ZnO+2HCl\longrightarrow  X+{H} _{2}O$
$ZnO+2NaOH\longrightarrow  Y+{H} _{2}O$
Identify $X,Y$ and the nature of $ZnO$ best described by the above reaction

  1. $X=Zn{Cl} _{2}$; $Y=NaZn{O} _{2}$; Nature of $ZnO$- Amphoteric
  2. $X=Zn{Cl} _{2}$; $Y={Na} _{2}Zn{O} _{2}$; Nature of $ZnO$- Amphoteric
  3. $X=Zn{Cl} _{2}$; $Y=NaZn{O} _{2}$; Nature of $ZnO$- Acidic
  4. $X=Zn{Cl} _{3}$; $Y=Zn{OH} _{2}$; Nature of $ZnO$- Basic
Reveal answer Fill a bubble to check yourself
B Correct answer
Explanation

ZnO reacts with HCl to form ZnCl2 and water, and with NaOH to form Na2ZnO2 (sodium zincate) and water. This dual behavior confirms that ZnO is amphoteric.

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

An oxide which forms salts when it reacts with both acids and alkali is :

  1. acidic oxide

  2. basic oxide

  3. amphoteric oxide

  4. none of the above
Reveal answer Fill a bubble to check yourself
C Correct answer
Explanation

An oxide which forms salts when it reacts with both acids and alkali is knwn as amphoteric oxides. $e.g.$ $Al _2O _3$.