Metal oxides and non metal oxides - class-X

On adding iodine to caustic soda(alkali), hypoiodites are formed and the peculiar smell is of iodoform and pale yellow in color.

Metallic oxides react with acids to give salts and water, similar to the reaction of a base with an acid, metallic oxides are said to be basic oxides.

The general reaction between a metal oxide and an acid can be written as : 

Metal oxides always reacts with acid to form salt and water. Copper oxide when reacts with $HCl$ it forms blue-green copper(II) chloride. 

The non-metal oxides can be neutralized with a base to form a salt and water.

Sulphur, nitrogen and phosphorus are non-metals and form non-metallic oxides. $H _2SO _4$ is an acid. 

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

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

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

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

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

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.

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.

$SO _3$ 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

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.

$Cu(II) oxide\longrightarrow CuO$

Metals oxides will react with dilute acids to give a salt and water. The metal replaces the hydrogen. 

When a metal oxide reacts with a base corresponding salt and water are produced.

Some metal oxides are acidic or amphoteric in nature and form salts with base in neutralization reaction. For example, aluminum oxide reacts with sodium hydroxide to form sodium aluminate.

Acid gets neutralized when it reacts with a metal oxide to give salt and water. 
Magnesium hydroxide + hydrochloric acid $\rightarrow$ magnesium chloride + water
$ Mg(OH) _2(s) + 2HCl(aq) \rightarrow MgCl _2(aq) + 2H _2O(l) $

The non-metal oxides can be neutralized with a base to form a salt and water.
$ SO _3(g) + Ba(OH) _2(aq) \rightarrow BaSO _4(aq) + H _2O(l) $

The other reactant is calcium hydroxide.
$ Ca(OH) _2   +    CO _2 \rightarrow CaCO _3 + H _2O $

Neutral non-metallic oxides are oxides of non-metal that neither neutralizes acids or base, example $CO,\ NO$ and $H _2O$.

When sodium hydroxide reacts with carbon dioxide it gives washing soda, also known as sodium carbonate and water.
$2 NaOH + CO _2  \rightarrow  Na _2CO _3 + H _2O $

The addition of water to a non-metal oxide results in a compound that consists of a non-metal atom surrounded by oxo ($=O$) and hydroxyl ($-OH$) groups. 

When ferrous oxide reacts with nitric acid, the products obtained are ferric nitrate, $NO$ and water.
$3FeO + 10HNO _3 \rightarrow 3Fe(NO _3) _3 + NO + 5H _2O$

Wen $CuO$ reacts with nitric acid, $CuNO _3$ and water are obtained.
$CuO + 2HNO _3 \rightarrow Cu(NO _3) _2 + H _2O$

The reaction of $CuO$ with sulphuric acid gives copper sulphate.
$\displaystyle CuO + H _2SO _4 \rightarrow CuSO _4 + H _2O$

Carbon dioxide reacts with calcium hydroxide to form calcium carbonate and water.
$\displaystyle Ca(OH) _2 + CO _2 \rightarrow CaCO _3 + H _2O$

When few drops of dil. $HCl$ is added to a small amount of red copper oxide, the colour of solution becomes blue due to the formation of chloride of copper $CuCl _2$.
$\displaystyle CuO + 2HCl \rightarrow CuCl _2 + H _2O$

The products of the reaction between $NaOH$ and sulphur dioxide are either $NaHSO _3$ or $Na _2SO _3$
$SO _2 + NaOH \rightarrow NaHSO _3$
$SO _2 + 2NaOH \rightarrow  Na _2SO _3 + H _2O$

In the given reaction calcium hydroxide which is a base reacts with carbon dioxide to give salt and water. So, carbon dioxide will be acidic in nature because acid and base reacts to give salt and water. nature.

When $MgO$ reacts with $HCl$, the products obtained are $MgCl _2$ and water.

We can conclude that sulphr dioxide is acidic in nature as it reacts with a base $(NaOH)$ to form salt and water.
$SO _2 + NaOH \rightarrow NaHSO _3$
$SO _2 + 2NaOH \rightarrow  Na _2SO _3 + H _2O$

We can conclude that $NO _2$ is acidic in nature as it reacts with a base $(NaOH)$ to form salt and water.

The reaction between dinitrogen trioxide and $KOH$ gives $KNO _2$.
$N _2O _3 + 2KOH  \rightarrow 2KNO _2 + H _2O$

When NaOH reacts with $NO _2$, the products obtained are $NaNO _2$ and $NaNO _3$
$2NaOH + 2NO _2 \rightarrow NaNO _2 + NaNO _3 + H _2O$

Acid and base react together, neutralize each other and form salt and water.

Given statement is true. Since water is also formed along with salt .

Option $(C)$ is the correct answer.
$Chlorine$ is evolved by the action of $\displaystyle HCl$ on $\displaystyle KMnO _4$
$\displaystyle 2KMnO _4+16HCl \rightarrow 2KCl + 2MnCl _2+8H _2O + 5Cl _2$

$H _3PO _3$ is a dibasic acid. In its structure, one oxygen atom is bonded to $P-$ atom via a double bond. $2$ $O-$atoms are bonded to $H-$atoms causing acidity. The third $H$ is directly attached to $P-$ atom responsible for its reducing behavior.