Tag: chemical bond and chemical equation

Questions Related to chemical bond and chemical equation

Addition of acid to water results in the formation of:

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. $H _2O$

  2. $H _3O^+$

  3. both A and B

  4. none of the above

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Correct Option: B
Explanation:

Addition of acid to water results in the formation of $H _3O^+$.

$H^++H _2O \rightarrow H _3O^+$

Which of the following types of solid is most likely to be soft, have low melting point and don't conduct electricity when melted?

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. Ionic

  2. Molecular

  3. Covalent

  4. Metallic

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Correct Option: C
Explanation:

Covalent compunds are soft(due to presence of cloud of electrons between the bonding atoms), have low melting point(due to weak forces of attraction) and are bad conductors of electricity in the molten state(due to lack of free electrons)

In the coordinate covalency,

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. electrons are equally shared by the atoms

  2. electrons of one atom are shared between the two atoms

  3. hydrogen bond is formed

  4. none of the above

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Correct Option: B
Explanation:

The 2 electrons of an atom( generally lone pair) is donated by one atom to the other atom and it results in the formation of a coordinate bond.

In which molecule co-ordinate bond is present ?

chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

  1. $H _2O$

  2. $NH _3$

  3. $CH _3NO _2$

  4. $CCl _4$

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Correct Option: B

During the formation of hydronium ion, water molecule acts as donor.

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. True

  2. False

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Correct Option: A
Explanation:

A hydronium ion is written as ${ H } _{ 3 }{ O }^{ + }$. 

It is formed when something else donates a proton, or $H^+$ to a water molecule.
The $H^+$ will easily bond to one of the two lone pairs of electrons around the water molecule.

     ${ H }^{ + }+{ H } _{ 2 }O\longrightarrow { H } _{ 3 }{ O }^{ + }$

Which response includes only the true statements concerning the characteristics of covalent compounds?
$I$. These compounds can be gases, liquids, or solids with low melting points.
$II$. Most are soluble in polar solvents.
$III$. Liquid and molten compounds do not conduct electricity.
$IV$. Aqueous solutions of these compounds are very good conductors of electricity.

chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

  1. $I$ and $III$

  2. $II$ and $IV$

  3. $I,III$ and $IV$

  4. $I,II$ and $III$

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Correct Option: D
Explanation:

I , II and III statement about covalent compounds are correct but the IV one is not correct since the aqueous solution of the covalent compound do not contain free ions and thus are not the good conductors of electricity .

The pH of pure water at 25°C and 35°C are 7 and 6 respectively. The heat of formation  of water from ${H^ - }$  and $O{H^ - }$ will be :

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. -77.11

  2. -84.55

  3. -92.36

  4. -66.25

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Correct Option: A

Dative bond is present in the molecule :

chemistry chemical bond and chemical equation coordinate bond types of bonds and properties chemical bonding and structure

  1. $NH _3$

  2. $CO _2$

  3. $NaCl$

  4. None of these.

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Correct Option: D
Explanation:
A dative bond is a covalent bond between two atoms where one of the atoms provides both electrons that form the bond i.e. a kind of 2-center, 2-electron bond.

Here, covalent bond is present in $NH _3$ and $CO _2$, whereas ionic bond is present in $NaCl$.

So, there is no dative bond in  $NH _3$, $CO _2$ and $NaCl$.

Hence, option (D) is the correct answer.

If pure $'p'$ orbitals are involved in molecule formation, then the shape of ${ H } _{ 3 }{ O }^{ + }$ will be:

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. pyramidal

  2. tetrahedral

  3. angular

  4. planar

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Correct Option: A
Explanation:

$ H _3O^+$ will have three bond pairs and one lone pair and shape same as $NH _3$ is therefore pyramidal. The hydroxonium ion is isoelectronic with ammonia and has an identical shape of pyramidal. 

So option $A$ is the correct option. 

The dative bond is present in:

chemistry chemical bonding and structure coordinate bond types of bonds and properties chemical bond and chemical equation

  1. $NH _{3}$

  2. $NH _{4}Cl$

  3. $PCl _{5}$

  4. $BF _{3}$

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Correct Option: A
Explanation:

When ammonium is formed, the fourth hydrogen is formed is attached by dative covalent bond because the only hydrogen nucleus is transferred from chlorine to nitrogen. The hydrogen electron left behind on the chlorine to form the negative chloride ion.