Tag: reactions of acids and bases

Questions Related to reactions of acids and bases

Sulphuric acid reacts with cupric oxide to give:

  1. copper sulphate

  2. cuprous sulphate

  3. no reaction

  4. it converts to cuprous oxide.


Correct Option: A
Explanation:

$H _2SO _4 + CuO \rightarrow CuSO _4 + H _2O$


Sulphuric acid reacts with cupric oxide to give copper sulphate and water. 

Hence, the correct option is $\text{A}$

Which of these is a non-metallic oxide which reacts with base to form salt and water?

  1. Carbon dioxide

  2. Carbon monoxide

  3. Both A and B

  4. None of these


Correct Option: A
Explanation:

Only carbondioxide reacts with base to form salt and water. Carbon monoxide does not give this reaction. 

The oxide that can form salt and water with a base as well as with an acid is :

  1. carbon monoxide

  2. sulphur dioxide

  3. sodium Oxide

  4. aluminium oxide


Correct Option: D
Explanation:

Aluminium oxide is an amphoteric oxide. It can react with both with an acid and a base to form salt and water. 

The reaction between copper oxide and nitric acid forms:

  1. copper nitrate and hydrogen

  2. copper nitrite and water

  3. copper nitrite and hydrogen

  4. copper nitrate and water


Correct Option: D
Explanation:

$CuO + 2HNO _3 \rightarrow Cu(NO _3) _2 + H _2O$

Copper oxide and nitric acid react to give copper nitrate and water.

When magnesium oxide reacts with $HCl$, it gives:

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

  2. ${O} _{2}$

  3. salt and water

  4. $MgCl _2$


Correct Option: C
Explanation:

When magnesium oxide reacts with $HCl$, it gives salt and water
$\displaystyle MgO + 2HCl \rightarrow MgCl _2 + H _2O$

The black color of copper oxide turns blue on treating with $HCl$ because of:

  1. formation of cupric chloride

  2. formation of water

  3. release of hydrogen

  4. release of carbon dioxide


Correct Option: A
Explanation:

When $HCl$ reacts with copper oxide, the black color of copper oxide turns blue due to formation of its corresponding salt i.e. calcium chloride. Water is formed along with salt.

The more non-metallic character of an element represents,  _______  oxide.

  1. less acidic

  2. more acidic

  3. neutral

  4. more basic


Correct Option: B
Explanation:

Generally, more metallic character of an element represent, formation of more basic oxide. Likewise, the more non-metallic character an element has, the more acidic oxide. The metallic character of an element can be determined by its position on the periodic table.

$SO _3 + Mg(OH) _2 \rightarrow $

  1. no reaction

  2. $Mg(OH) _2$

  3. $Mg(SO _4)$

  4. $H _2O$


Correct Option: C,D
Explanation:

$SO _3$ is a non-metallic oxide which is acidic in nature and reacts with base to give a general neutralization reaction by forming a salt and water as


$SO _3+Mg(OH) _2\rightarrow MgSO _4+H _2O$
                                            Salt        water
Correct option - C,D

The formation of metal oxide on the surface of metal is called:

  1. cathodising

  2. anodizing

  3. acidification

  4. none of above


Correct Option: B
Explanation:

The formation of metal oxide on the surface of metal is called anodizing. For example: aluminium oxide is formed on the surface of aluminium when it is exposed to air which prevents its corrosion.

Black copper (II) oxide dissolves in colourless sulfuric acid to give:

  1. yellow solution of copper (II) sulfate

  2. blue solution of copper (II) sulfuric acid

  3. blue solution of copper (II) sulfate

  4. none of above


Correct Option: C
Explanation:

$Cu(II) oxide\longrightarrow CuO$


$CuO+ H _2SO _4\longrightarrow \underbrace{CuSO _4} _{(Blue\quad coloured)}+H _2O$

Copper(IIoxide, a black solid and colourless dilute sulfuric acid react to produce copper(II) sulfate, giving a characteristic blue colour to the solution.

Hence, the corret option is $C$